Introduction, credits, and disclaimer
This document is primarily a course outline for one of the Canadian Gun Nutz seminars about M-14 type rifles. These seminars are designed to share information with M-14 owners, of whatever brand, so that they can competently inspect and evaluate their personal M-14 type rifle, and make sound judgments regarding safety, upgrades, and value, and also to provide them with a realistic perspective on what jobs they can do themselves, and what should be reserved for the competent M-14 experienced gunsmith.
The following document is NOT to be taken as criticism of any manufacturer, importer, retailer, gunsmith, accessory manufacturer, or private seller of the M-14 type riflesMost of these people deserve our respect, and our money. Remember, if they don’t get both, then they won’t stay in business long enough to keep feeding our M-14 obsession.
As with any other free advice you get, especially free advice from the internet, remember,
“Free advice is often worth a lot less than you paid for it”,
And of course,
“Your personal mileage may vary.”
Remember also that at this time, the supply of M-14 type rifles, old or new, is limited,
and that there will be no more new Chinese or original US GI M-14 type rifles coming to market in the foreseeable future.
Like the great Canuck philosopher HUNGRY says,
“Don’t buy one … buy two …”
and get them quick,
before the supply runs out,
and your #### falls off”.
Inspecting your M-14
This is an FAQ about what to look for when you get your brand new Chinese M-14 or Springfield Armory M1A or well used genuine US GI M-14. Even though a properly built M-14 in good condition can be one of the most reliable mechanical devices known to mankind, and even though the manufacturer of a new rifle, or the seller of a used rifle, always says that everything is just fine, it is always a good idea to check over any new firearm for yourself.
NOTE: With your brand new M-14 type rifle, American OR Chinese, the inspection report included will always show that all the inspection boxes are checked off as "GOOD".
BUT,
even with that perfect score on the paper report, your brand new rifle just might have some serious deficiencies. Irregardless of what any supplier or manufacturer or vendor says about their “stringent quality control”, some of them are still selling NEW M-14 type rifles with;
- barrels indexed so far off, that this is immediately obvious to any cursory inspection.
- headspace greatly exceeding SAAMI specifications for .308 Winchester commercial ammunition, even though the firearm may be clearly marked with that caliber
- bolts that may be bearing on only on lug
- bolts that spit out the extractor after the first few round
- improperly hardened or cast parts that wear or break within a few rounds
The only reasonable conclusion we can reach is that, no matter what the glowing Quality Control checklist that comes with the rifle may say, these suppliers do NOT do even a cursory inspection before shipping you your new rifle.
Norinco VS Springfield …a Canadian perspective
Norinco M14 rifles are made primarily of FORGED parts, with excellent dimensional tolerances, but with some possible variations in heat treatment and assembly. In Canada, if you buy your new or used Chinese M-14 from a reputable dealer, you will probably have some type of warranty. The vendor may also have some spare parts, and a repair/maintenance service, to keep your Chinese import shooting as long as you want. With the recent explosion in popularity of the Chinese M-14 type rifle in the Canadian market s, there is a wealth of information, accessories and services available in Canada to support these fine firearms.
If you view the Norinco [ M-305 or M-14 or M-14S ] as only a stripped FORGED receiver, with very close to US GI dimensional specifications, you can never go wrong. Think of all those extra parts that come attached to the receiver as [ mostly usable ] free bonuses. If you like a hands on, do it yourself project, get a Chinese M-14 Simply do a bit of tuning, add the requisite US GI parts, and you have one of the best rifles available, and at only 1/3 or so of the cost of an equivalent Springfield M1A.
BUT,
for those who don't want to get their hands dirty working on their own rifles, or who don’t want to pay for a gunsmith to do it for them, the Springfield M1A can be a very good choice. Springfield offers a lifetime warranty on the M1A. Unfortunately, this lifetime warranty may be required even on a brand new Springfield, because, in my experience [ and in many other M1A owner’s experience ] there may not be much difference in quality control between the new US and the new Chinese made versions, There have been considerable complaints that many of the M1A CAST receivers are not correct dimensionally. Aside from the CAST receiver, new Springfield M1A rifles no longer use surplus US GI internal parts, and in their place, SA has turned to more cast parts, of varying quality, from various suppliers.
Known Springfield Armory M1A deficiencies
Springfield Armory, Inc. M1A rifles may have some or all of the following deficiencies:
1) The receiver scope mounting hole and mount surfaces may be out of specification, which makes fitting non-adjustable scope mounts difficult.
2.) The receiver bridge primary (bolt closing) firing pin retracting surface can be mislocated. The camming surface of the tang on the firing pin should be inspected carefully for damage. If the firing pin tang is damaged, the firing pin should be replaced with a non-chromed firing pin. With firing pins that are not chromium plated, most of the damage will be on the firing pin instead of the receiver bridge. The harder surface of the chromium plated firing pin will cut a groove into the receiver bridge deeper and sooner .. Note that light polish wear is normal on the retracting surface but a groove cut into the receiver by the firing pin is not.
3) The bolt may be cast, and have cast parts. These cast bolts are not top quality, and especially have a bad habit of losing the cast extractor
4) The receiver locking lug engagement surface is slightly misaligned. Lapping the bolt to the receiver can resolve this, and is recommended to evenly distributes stress on the receiver.
5) The bottom of the bolt roller makes contact with the receiver when the bolt is in battery, preventing the bolt from closing completely. The fix is to grind a half round relief cut into the receiver, to accept the bolt roller when fully locked in the down position. This will save replacing the bolt or bolt roller, which otherwise could be destroyed rather quickly.
6) The receiver groove that takes the tab of the op rod may be undersize, rough, vary in size, and not cut straight. This can cause rough functioning, unreliability, quick wear on that tiny op rod tab, and op rods eventually jumping out of the track. This also can cause extra work when properly fitting a replacement GI or Chinese op rod with an unworn, full size tab.
7.) The receiver rear sight elevation knob indexing detents wear prematurely due to too soft surface hardness. The fix is to install an elevation repair disk.
8.) The holes for the bolt lock pin are too small. The bolt lock roll pins could be forced in which may cause one of the bolt lock window receptors to break. The simple solution is to use a slightly smaller diameter pin.
9.) Some of the earlier Stainless Steel barreled “loaded” rifles, had the chambers cut TOO FAST = very rough = reamer chatter = poor extraction and reliability.
10.) The rear sight pocket is slightly too short. This results in a slight over hang of the rear sight base at the rear.. This springs the rear sight cover more than it should. The front edge of the cover can be lightly filed down, which requires less force to install the rear sight cover.
NEW Chinese M-14 rifles VS OLD Chinese M-14S or M305
I make a distinction between the OLD Chinese M-14 rifles, Polytech and Norinco, and the NEW Chinese M-14 rifles. The OLD Chinese M-14 clones came in to Canada and the US before the US assault rifle ban. The NEW Chinese M-14 clones are all Norinco, and over the years, these have arrived in Canada in various batches … most recently Nov 2007. These NEW 14s are slightly different and potentially better than the OLD. However, Chinese quality control varies considerably amongst individual rifles. Some of the old Chinese M-14 rifles were as good as it gets right out of the box, and can give years of safe, reliable service. Unfortunately, some of the Chinese M-14 rifles, new or old, can become unsafe to fire within a few hundred rounds.
To me, the most significant difference between the NEW and the OLD Chinese M-14 rifles is that the NEW batch of Norincos will take a “drop in” GI bolt. This was definitely NOT the case for the older Chinese M-14 rifles, Polytech and Norinco alike. On most of the old ones, the barrel hood protruded into the receiver about .010” too much, so that a GI bolt would require massive amounts of lapping in to fit up properly. So, for these Chinese M-14 type rifles, you usually needed to swap in a GI barrel, or do other major modifications when swapping in a GI bolt.
The next important difference is that the NEW Chinese M-14 rifles all seem to have the flash hiders permanently attached. This matters primarily if you want to swap out or work on the gas assembly, and /or swap to different style flash hiders or compensators. Taking off a welded on flash hider is NOT a trivial job. Also, the NEW batch has the tiny barrel retaining screw MEGA-torqued down, then MEGA-STAKED in. Getting this screw out is again non-trivial.
Another consideration between the NEW and the OLD Chinese M-14 rifles is that the NEW batch of Norinco's, in some cases, MAY have significantly improved quality control. I say “MAY”, because, while I have not seen any soft bolts recently, the bolts may still be fitted improperly, and may have way too much headspace. Also, on a sad new note, while I never saw a major misalignment of the barrel / receiver in the OLD models, this misalignment[ aka misindexing ] is epidemic with the NEW NORCs.
Known Chinese Norinco / Polytech M-14 / M-14S / M-305 deficiencies
First thing to understand about the Chinese M-14 clones, whatever manufacturer, and whenever they were made, is that Chinese quality control varies considerably amongst individual rifles.
While the Chinese FORGED receivers are usually closer to US GI dimensional specifications than most commercial receivers, with the Chinese M-14 clones, heat treatment and quality control during assembly of the fitted parts may vary considerably.
In my personal sampling [ several dozens ] careful inspections have found MOST [ about 2/3 ] of the Chinese M-14 rifles to be good to excellent overall, or else they could be made into great rifles with a bit of effort, and some US GI parts. I have also found a few receivers that were a bit softer than desirable, but these would still make safe and reliable shooters … they just might wear out a bit earlier. I also found one Chinese M-14 receiver that was heat treated too hard [ as in BRITTLE ]. This one was unfired, sold as a stripped receiver only, and it shattered while being fitted with a barrel. This was fortunate, as a receiver that is too hard is much more unsafe than one that is too soft, and without proper test equipment, is very difficult to detect.
This is why it is so important that the end user has as much knowledge as possible when buying any M-14 type rifle. A careful inspection can determine if you are getting a silk purse, perfect as is, or a sow’s ear, that will require lots of money and labor to get right.
1) Even brand new, the original Chinese bolt may be poorly fitted at the left locking lug, the bolt may be too soft, headspace may be grossly long for SAAMI .308 Winchester specifications even though the firearm is marked as .308 Winchester, headspace will almost definitely be too long for reloads using .308 Win brass, and bolt timing may be incorrect. … or all of the above.
Most of the NEW Norinco clones I've checked recently had about .009” - .013" headspace over 7.62 NATO GO. When you consider that SAAMI .308 Win NO GO is approximately equivalent to 7.62 NATO GO, you can see that if shooting .308 Win ammo in these lengthy chambers, the SAAMI THEORETICAL safety margins are being exceeded by quite a bit. That being said, in the real world, my personal Chinese M-14, new out of the box, had .009” headspace over 7.62 NATO GO. This particular rifle also shot a sub-moa group out of the box with factory loaded .308 Win 168 Gr HPBT match ammo. Here in Canada, we have thousands of these M-14 type rifles floating around with similar or even worse headspace measurements, and have very few [ or none? ] documented cases of too long M-14 headspace causing case separations with NEW commercial .308 factory loaded ammo.
If you want to reload for the M-14 rifles, or if you want target accuracy, or if you want that extra theoretical safety margin that tighter headspace can give you with .308 Win commercial ammo, then in most cases, the fix is relatively simple [ if a bit expensive ] … just replace the Chinese bolt with a US GI M-14 bolt. In most cases, with Chinese receivers and barrels in good condition, this takes only a few minutes of lapping in before almost perfect .308 Win GO headspace is achieved.
2.) The barrel may be incorrectly indexed to the receiver . If the front sight leans to the left, and the rear sight is adjusted to the right to compensate, then the barrel has been over-tightened. To correct this, the barrel must be removed, and the barrel shoulder must be rolled back to remove the metal distorted by this over-tightening. Since proper alignment, torque, and fit of the barrel shoulder to the receiver is critical to accuracy, this is not a trivial fix.
If the front sight leans to the right, and the rear sight is adjusted to the left to compensate, then the barrel is under-tightened. This is not as serious as over-tightening, as in most cases all that is required is to remove the little lock screw under the op rod at the receiver/barrel, and using the proper tools and torque specifications, tighten / rotate the barrel to the proper location. This is what is known as “INDEXING” the barrel
3) The Chinese op rod spring is undersize in diameter, and usually will not last as long as a US GI spring. Replacement with a US GI spring, even a well used GI spring, is the very first upgrade any Chinese M-14 owner should consider. NOTE: the Chinese op rod springs are smaller in inside diameter than the US GI springs. If fitting a US GI spring sized round style op rod spring guide, the Chinese springs may bind and cause reliability issues.
4) The hammer, trigger and sear, may be soft, and also may require a lot of fitting to get a safe trigger, with no creep, and a decent pull weight. The trigger pin and the hammer pin, as well as being soft, may also be undersize. An undersize pin that wears out of round quickly, does not contribute to a good trigger pull.
5.) The Chinese wood stock is made of mystery wood … some are as soft as balsa. This wood will compress under tension, or may swell when wet, and the result may be a trigger mechanism that is unsafe = the hammer will follow the bolt down if the trigger is held back during cycling, or also have an effect on fit when latching in magazines.
6.) The Chinese rear sight mechanism may be soft, and wear quickly to the point where adjustments are not possible, or won’t stay set. Again, replacement with US GI parts will fix.
Recommended Chinese M-14 Modifications
Above the cost of a basic/box stock Chinese rifle [ approximately $ 450 – 475 Canadian after shipping/taxes ] the costs to do up a Chinese M-14 properly are approximately …
REQUIRED:
$ 75 - Gunsmith inspection to check headspace, bolt fit and other issues.
$ 10 – US GI op rod spring
OPTIONAL [ in order of importance ]:
$ 75 – reindexing barrel [ if required ]
$ 130 – US GI Fiberglass stock
$ 20 - long op rod guide retaining pin [ or modify GI stock for short pin ]
$ 45 - SS one piece round/match op Rod spring guide
$ 50 – trigger job with stock Chinese parts
$ 80 – replacement US GI rear sight, M-14 or M1 Garand
$ 300 – US GI Bolt [ usually required for use with .308 commercial ammo ]
NOTE: some of the OLD Chinese will NOT take a GI bolt without also using a GI barrel
$ 250 – US GI Barrel
$ 40 ea - MAGS 20/5 - Chinese or $ 80 ea - USGI MAGS
$ 60 - US GI Hammer, trigger, and pins
After that, the sky is the limit.
Shorty / Bush / SOCOM estimate
Additional costs to do up a shorty are approximately :
$ 75 - shortening barrel
$ 75 - threading muzzle for flash hider and installing AR 15 type FH
$ 85 - front sight that fits on the gas assembly [ Gas Ring Front Sight ] NOTE: the gas lock threads are METRIC on the Chinese barrels, so a METRIC GRFS is required
7.62 NATO VS .308 Win
As a GROSS GENERALIZATION for newly manufactured ammunition, the variations in external cartridge dimensions between .308 Win and 7.62 NATO cases are not that significant. Ammunition from different manufacturers, between lots of ammo from the same manufacturer, and between individual rounds within a lot, may be greater than any theoretical differences in external dimensions between 7.62 NATO and .308 Win ammunition. However, there are other very significant differences between the two types of ammunition. One such difference is that 7.62 NATO brass is usually thicker, especially at the base. Also, the brass in 7.62 NATO cases generally seems to be tougher, perhaps drawn of a stronger alloy. This thicker 7.62 brass results in smaller internal volume with 7.62 cases, so load data and reloading data is NOT interchangeable between 7.62 NATO and .308 Winchester. In semi auto rifles, the tougher / thicker 7.62 NATO brass is better both for initial firing, and for potential reloading.
7.62 NATO military ammunition is carefully chosen to optimize performance in 7.62 NATO gas operated military rifles, like the M-14. This restricts the choices in internal and external ballistics considerably. On the other hand, .308 Winchester ammunition is designed for sporting or target use, with a wide range of intended targets, available in many bullet weights and bullet types, from many different manufactures. The really significant differences between 7.62 NATO and .308 Win ammunition may not be readily apparent, but they ARE there. Just as an example, 7.62 NATO ammunition may be loaded to higher pressures than SAAMI spec .308 Win. Bullet weights and pressure curves for 7.62 NATO take into account the inherent characteristics of a gas operated rifle, while commercial loaded .308 Win may not. Differences such as bullet weight, powder choices, retardant for the powder, Berdan or Boxer primer, crimped in primer, sealant at primer and bullet neck, crimped bullet, bullet weight, and bullet type, can all have a significant effect on safety, reliability, accuracy, and durability.
Headspace AKA … can I shoot .308 Win commercial ammo in my Chinese M-14S … after all it is marked .308 on the receiver?
Most .308 Win ammunition will function safely in a M-14 type rifle, if that rifle has .308 Win headspace. Headspace varies considerably with the M-14, clones or originals. The headspace of your individual M-14 type rifle will be the major consideration when determining if .308 will shoot safely. Most likely, the answer will be a qualified ... MAYBE?
If you stray too far from 7.62 NATO standards regarding bullet weight and pressure, you can get into durability, reliability, and accuracy issues. The M-14 was designed for 150 gr bullets, with military powders tailored to have the correct pressure characteristics at the gas port. The twist in the M-14 barrels likes 168 gr bullets for excellent accuracy. Those who choose heavier bullets at high velocity, for hunting or for long range target shooting, will have to be aware that recoil from these heavier bullets can do significant damage to the M-14 rifle. Those who go too light, either in bullets or in powder, may find the gas left over at the port may not have enough power to operate the mechanism reliably and consistently. That being said, I have tested a few M-14 rifles with the sabot loaded Remington .223 55 Gr Accelerators, and this makes for a reliable shooting load, with no recoil, that may be accurate in your individual M-14. As usual, with individual opinions and experience, your personal mileage may vary.
The M-14 rifle is incredibly sensitive to variations in ammunition, and some loads may shoot MOA out of your individual rifle, while others are closer to hour of angle. Best advice I can give on ammunition, is to try as many different brands, weights, and types of ammo, 7.62 NATO Ball and .308 Winchester, to find what your individual rifle likes. Then buy a case of it.
How do I measure the headspace of my M-14? AKA Headspace gages:
Measuring the headspace on an M-14 rifle is NOT rocket science, but it can be a bit complicated, especially if you don’t have all the proper tools and gauges, and know how to use them.
Forster Winchester .308 GO: 1.630"
Military # 7274780B GI "GAGE HEADSPACE" for 7.62 NATO GO: 1.6355"
NOTE: the .0055" extra of the military 7.62 GO is .0015" over the .308 Win NO GO of 1.634"
Also, the GI gage is cut out at the back for the ejector ... to allow you to measure headspace without taking the M-14 bolt apart.
NOTE: the commercial .308 Win gages are NOT cut out for the M-14 ejector, which is spring loaded with enough power to launch it clear across your living room into the darkest corner, and into the deepest part of your shag rug. This incredible spring tension will bear directly on any gage that is not relieved for the ejector, and trying to measure headspace when the gage is being forced into the chamber, and the bolt is being forced into the receiver, is not …repeat NOT …accurate. If you are using a commercial gage that is not relieved for the ejector on an M-14, then you MUST strip the bolt first before trying to measure the headspace
I have both .308 and Mil Spec 7.62 GO gauges, and find I really don’t need any more. With a set of feeler gauges, I can get quick and easy headspace estimates, from zero on up to very scary. This method uses the gage and the feelers to measures only the dimensions of the gap between the right side of the receiver, and the right bolt lug. If the bolt is straight, and if the wear pattern on the bolt lugs shows that the bolt is bearing evenly on both sides, then and only then, you can extrapolate that the left lug has the same gap dimension. If you want more precise measurements, without resorting to a {VERY EXPENSIVE ] set of custom gauges in .001” increments, you can make a set of spacers by cutting up a cheap set of automotive feeler gauges. Stack them up on your GO gauge, using thin grease to hold them together, and you will have as close to a perfect measurement as you can get, without resorting to expensive tools.
What should the headspace be on an M-14 type rifle?
For rack grade M-14 rifles7.62 NATO GO is 1.6355” [ very close to .308 NO GO ]
7.62 NATO Field Reject is either , DEPENDING ON SOURCE., 1.6415” or 1.6445,
NOTE, however, that the overhaul procedure for rack grade M-14 rifles specified -
“ … to maximize barrel life (with 7.62 x 51 mm NATO ammunition)
every effort should be made to keep maximum headspace no more than 1.6375 ".
M-14 National Match headspace standards are as follows:
GO 1.633"
NO GO 1.636"
NOTE: These recommendations are for US GI 7.62X51 NATO mil spec ammunition in a CAREFULLY cleaned and maintained match rifle
MAXIMUM Headspace:
When it comes to "real world" headspace, relying on headspace gages alone can provide only a precise measurement of chamber length. The other part of the equation is ammunition dimensions. So, unless you measure brass before and after firing, even in best case scenarios using a gage to measure headspace is always going to be a "best guesstimate
.308 Win "SAAMI" FIELD REJECT is 1.638". Although I have never personally seen it or read of a documented case, in theory, some commercial .308 Win cartridge cases may fail with a case separation on the first firing at .308 NO GO.
If your headspace is 1.638" - 1.6445", you should use only 7.62x51 NATO mil spec ammo.
If your headspace is 1.6445" or longer, even with mil spec7.62 NATO ammunition,
the chamber may be too long for safe use .
MINIMUM Headspace:
Chambers which are too tight may actually be detrimental to accuracy, reliability and safety. Also, semi auto rifles with tight chambers will require more cleaning to be reliable and or safe. If your headspace is less than 1.632", you may find the chamber too tight with some brands of .308 Win or 7.62NATO ammo. With short chamber, the case neck might be squeezed, or the bullet might be pushed back by the lands, both of which can disrupt accuracy and up pressure. Plus, with the M-14 "floating "firing pin, short chambers can increase the risk of “slam fires" especially with soft commercial primers. Finally, reloading ammo for a tight chamber may require small base dies, case trimming, and immaculate case preparation.
When fitting M-14 headspace for new "Match" rifles, I first lap the bolt in for proper maximum contact. Then I try for 1.632" headspace [ Forster .308 Win GO gage + .002" shim cut from a feeler gage, bolt stripped to ensure ejector tension does not push gage forward ]. This measurement is usually capable of turning a STRIPPED bolt all the way down easily on most brands of NEW FACTORY .308 or 7.62 NATO ammunition. The test cartridge should fall easily out of the chamber, and there should NOT be any major marks or deformation. Remember, you are not trying to resize the cartridge with the rifle.
Bolt to Receiver Fit …. What is the left lug doing?
From a safety perspective, bolt lug to receiver fit can be much more critical than headspace. With the M-14 rifle, headspace is only one part of the bolt fit equation. Far too many Chinese M-14 rifles, new and old, and even some brand new M1A rifles, have the left bolt lug cut or fitted improperly. If the left bolt locking lug shows signs of being hand ground by a Dremel like implement, the possibility exists that are you are shooting with only the right locking lug engaging properly. This is much more important than a few thou headspace, but even here, most of these bolts don't cause safety problems UNLESS they are also very soft. If you also have a soft bolt with a left locking lug that is cut at too acute an angle, then in a few hundred rounds the left lug peens back, the bolt face gets cocked excess headspace can get very scary . BTDT … seen several of the OLD Chinese M-14 bolts like this.
With the M-14, which has a very tiny and complicated left locking lug design, the bolt should be bearing EVENLY on BOTH lugs, and the bearing should be maximum. … especially at that awkward left lug. This is easily seen on a used M-14 type rifle by checking the wear patterns on the bolt lugs. On a new bolt, the way to check fit is to clean and dry the lugs in both bolt and receiver, and use a permanent felt pen [ RED is nice ] to mark the bolt lugs. With slight rearward tension, work the bolt up and down a few dozen times, remove the bolt, and inspect the wear pattern scraped out of the red ink. What you are looking for is EVEN wear on the locking lugs, with MAXIMUM bearing on BOTH lugs
This well known and too common defect in clone M-14 rifles, is why a USGI bolt swap is such a great idea. USGI bolts go for about $ 300 these days, and a $300 upgrade to a $399 Chinese rifle may not make much sense ... until you consider that with a few minutes work lapping the bolt to the receiver, and a few other bits, you can end up with a Chinese / US GI crossbreed that is totally reliable, and as good a shooter as a Springfield M1A that costs several times as much. And that brand new expensive M1A might still need a new GI bolt to replace a cast bolt.
PS: Not all the OLD Chinese M-14 clones have this problem … I would estimate only about 1 in 3. Recently I picked up an old Chinese M-14S at a gun show. It was ancient, stored 20 years or more, but it was almost unfired. Checking the fit of the original Chinese bolt showed almost perfect bolt lug mating to receiver, and headspace was .308 GO plus .002", which is PERFECT!!
Detailed inspection … front to back
1.) Flashider: Is it welded on? Is it loose? Is the castle nut on tight and locked in place by the set screw? Is the set screw loose.? Is the FH on straight? Can you see any indications that bullets are hitting the FH? Has it been reamed to NM specs? Is it cast? Is it cracked? Is it pitted and corroded? Does it have a bayonet lug? Does it have slots, or is it completely closed? Does the rifle “sing” when the bolt slams forward on an empty chamber?
2.) Front sight: is it straight = vertical or is it rotated to one side or the other, indicating expensive reindexing? Is it loose? Is the square at the top? Is it set way off to one side? Is the sight retaining set screw there? Is it the narrower NM sight?
3.) Barrel: is it bent? Is it tight to the receiver? Is the op rod guide tight? Is the op rod guide aligned correctly so the op rod meets the gas piston center? Is the bore chromed? Pitted? Is the chamber smooth … or are there reaming marks visible?
4.) Gas Assembly: is it loose = rotation? Slides back and forth? Is it misaligned? Is the gas assembly plug tight? Does the gas assembly line up with the hole in the barrel? Is the gas turn off valve vertical or horizontal? Is the bore of the gas assembly corroded or worn? Does the piston move freely and smoothly? Is the piston chipped or peened? Is there carbon built up inside the gas assembly or the piston? Does the ferrule rattle? Does the hand guard ferrule tension correctly to the stock?
5.) Op rod: Chinese op rods are forged one piece, same as the best US GI TRW op rods. Chinese op rods are usually good for hardness. Check for tab wear, bends, and cracking? Springfield op rods are often US GI, but if not, they may be cast, and vary considerably in quality. US GI op rods are, of course , the best, but most are now well worn, and rewelds from scrap pieces may be on the market. Check the weld on any two piece US GI op rods for cracks and voids. Check for bends, and that the op rod runs straight in the receiver groove?
6.) Receiver: Field test check for softness … run a file lightly over some hidden spot see if file catches and cuts easily … if so, this receiver is too soft for long term durability. Reheat treatment may be desirable. Look for any obvious burrs, cracks, or rough spots? Some of the NEW Chinese receivers have the top of the receiver right locking lug corner cut square [ and sharp enough to cut yourself ]. This corner should provide a smooth transition between vertical to horizontal motion, and should be softly rounded and smooth. Some of the OLD Springfield Armory M1A receivers do NOT have enough clearance under the bolt roller, to allow the bolt to close completely. This will slam the bolt roller between the receiver and the op rod … which is not a good thing. Simple solution for the sharp right lug corner, and no bolt roller clearance … a Dremel with a ½” wheel. Also check at the rear, where the tang of the safety rotates against the receiver … is there a groove worn into the receiver by the tang?
Other than the above, checking the receiver for proper dimension is a job for a professional with the right tools. However, every Chinese receiver I’ve personally inspected was as good or close to US GI dimensions. Odds of you getting a bad Chinese receiver are very slim. If this is a cast commercial receiver, odds of getting some dimensional variations are very high. Whether these variations will significantly effect performance is again best left to a professional to determine. As an example, with the last Springfield M1A receiver I built up into a full house target rifle, the bolt lapping with a NEW GI TRW bolt took about 30 minutes to achieve proper bearing on both lugs. It also took about 3 hours to fit a near new TRW one piece op rod. The final product was as good as it gets, but it did take a LOT longer to fit the GI parts, than would be usual with a Chinese FORGED receiver.
7.) BOLT: inspect the left locking lug … does it look like it was hand ground with a Dremel tool? If so it may not be properly fitted to the left locking lug. On a used bolt, check the wear patterns. On a new bolt, get some RED permanent marker ink on the lug surfaces, and inspect the seating. Does the bolt engagement provide maximum bearing evenly on both lugs? Extractor fit? Ejector spring tension? Firing pin protrusion? Timing? firing pin tang wear ?
Test fire … go to the range and load only two rounds in the magazine … test fire one round … see if the rifle doubles? eject the second round from the chamber and look at the primer dimpling? … yes, the M-14 has a floating firing pin, with no spring to keep it away from the primers. Yes, this is scary, but on a properly set up M-14, using proper ammunition, you will not get a slam fire.
At the last WET Coast M-14 seminar, we had one bolt that had a bit of brass stuck in the firing pin hole. This is not that uncommon with these rifles, especially if the firing pin hole is worn, or the pin tip is chipped. PAY ATTENTION HERE ... this is definitely not a good thing [ aka "INSTANT DEATH or SLAMFIRE" ].
Because the firing pin is the inertial design, with NO RETACTING SPRING, it is a very good idea to check that firing pin hole from time to time, to see if any crud [ especially primer shavings ] is building up in there. While the firing pin/receiver camming action SHOULD still retract the firing pin even with a bit of garbage clogging the system, this is not something you want to test for your self. A clean rifle is a happy rifle ... and a lot safer too.
Which leads to the scary question ... how do you take that bolt apart??? There are enough horror stories about M-14 bolt dissambly [ that ejector spring launches the ejector with enough power to pierce your eyeball and embed itself in your brain ...yadayadyada ] that it might pay to invest in one of the bolt disassembly tools. The tool makes it simple to disaasemble the inside gubbins, and keep the firing pin channel clean.
8.) Rear Sight: Is the rear sight tight, or does it move around a lot if you wiggle the aperture arm? Is the hole in the rear sight centered? Does the rear sight move up and down? Does the rear sight adjust left to right? Does the sight stay set ?
9.) Trigger group: does the trigger group lock in with a bit of spring [ about ½” of tension ]? Does the safety lock the firing mechanism when engaged? Does the safety move with correct tension? With no magazine in the rifle, hammer cocked, and safety on, does the hammer follow if you drop the bolt on an empty chamber? Try this again with the safety off to test the front hooks on the hammer? Now, with the trigger held back, test the rear hooks on the hammer by trying this again? Is the trigger pull creepy? What is the weight of the trigger pull? Measure it carefully …4 and 1/2 lbs is the MINIMUM safe weight. If it is less than 4 ½ lbs, then the hammer may follow in some circumstances. … especially if the rifle is not held tightly against the shoulder.
NOTE: changing stocks on the M-14 rifle can definitely change the way the trigger functions, so every time you swap the stock on an M-14 type rifle, you should do this trigger group safety check again.
.At the range, after performing test firing for test # 7, load five rounds … hold the rifle loosely … and fire all five rounds. With the rifle held loosely, did it double … or worse yet, run away with the whole magazine?
10.) Magazine: Pinned correctly to meet Candian firearms laws to 5 rds ONLY? Latches in the receiver tightly? Bent lips? Dents? Follower? Spring?
11.) Stock: Is the receiver tight to the bedding lugs? Receiver tight at top rear bedding surface? Does the receiver slide back and forth in the stock? Are the bearing surfaces for the trigger guard compressed in? Does the trigger guard lock in with correct tension? Is the front of stock tight against the ferrule? Ferrule greased? Hand guard cracked? Loose? Clearances at top of fore stock? Butt plate bent? If using a GI stock with a clone, has the connector lock pin been replaced with a longer one, or has the stock been padded to keep the shorter commercial connector lock from shuffling out? If using a Fiberglass GI stock, does the butt plate have the correct top screw, nut and nut retainer?
12.) Accessories: did you get a complete cleaning kit? Have you looked in the butt trap? Did you get a sling? Bayonet? Spare Magaziness?
13.) Scope mount … is this one of the very few gawdawfulexpensive scope mounts recommended by the CGN scope mount FAQs that will actually work, or is it cheap no name TRASH??? If you paid a lot less for it than you did for the rifle, then it is most likely TRASH. If you can shoot better with Iron sights than you can with a scope, then your scope mount is loose … and is probably TRASH.
PS: did you get the message yet … there are a lot of scope mounts out there for the M-14, but most of them are TRASH..
This document is primarily a course outline for one of the Canadian Gun Nutz seminars about M-14 type rifles. These seminars are designed to share information with M-14 owners, of whatever brand, so that they can competently inspect and evaluate their personal M-14 type rifle, and make sound judgments regarding safety, upgrades, and value, and also to provide them with a realistic perspective on what jobs they can do themselves, and what should be reserved for the competent M-14 experienced gunsmith.
The following document is NOT to be taken as criticism of any manufacturer, importer, retailer, gunsmith, accessory manufacturer, or private seller of the M-14 type riflesMost of these people deserve our respect, and our money. Remember, if they don’t get both, then they won’t stay in business long enough to keep feeding our M-14 obsession.
As with any other free advice you get, especially free advice from the internet, remember,
“Free advice is often worth a lot less than you paid for it”,
And of course,
“Your personal mileage may vary.”
Remember also that at this time, the supply of M-14 type rifles, old or new, is limited,
and that there will be no more new Chinese or original US GI M-14 type rifles coming to market in the foreseeable future.
Like the great Canuck philosopher HUNGRY says,
“Don’t buy one … buy two …”
and get them quick,
before the supply runs out,
and your #### falls off”.
Inspecting your M-14
This is an FAQ about what to look for when you get your brand new Chinese M-14 or Springfield Armory M1A or well used genuine US GI M-14. Even though a properly built M-14 in good condition can be one of the most reliable mechanical devices known to mankind, and even though the manufacturer of a new rifle, or the seller of a used rifle, always says that everything is just fine, it is always a good idea to check over any new firearm for yourself.
NOTE: With your brand new M-14 type rifle, American OR Chinese, the inspection report included will always show that all the inspection boxes are checked off as "GOOD".
BUT,
even with that perfect score on the paper report, your brand new rifle just might have some serious deficiencies. Irregardless of what any supplier or manufacturer or vendor says about their “stringent quality control”, some of them are still selling NEW M-14 type rifles with;
- barrels indexed so far off, that this is immediately obvious to any cursory inspection.
- headspace greatly exceeding SAAMI specifications for .308 Winchester commercial ammunition, even though the firearm may be clearly marked with that caliber
- bolts that may be bearing on only on lug
- bolts that spit out the extractor after the first few round
- improperly hardened or cast parts that wear or break within a few rounds
The only reasonable conclusion we can reach is that, no matter what the glowing Quality Control checklist that comes with the rifle may say, these suppliers do NOT do even a cursory inspection before shipping you your new rifle.
Norinco VS Springfield …a Canadian perspective
Norinco M14 rifles are made primarily of FORGED parts, with excellent dimensional tolerances, but with some possible variations in heat treatment and assembly. In Canada, if you buy your new or used Chinese M-14 from a reputable dealer, you will probably have some type of warranty. The vendor may also have some spare parts, and a repair/maintenance service, to keep your Chinese import shooting as long as you want. With the recent explosion in popularity of the Chinese M-14 type rifle in the Canadian market s, there is a wealth of information, accessories and services available in Canada to support these fine firearms.
If you view the Norinco [ M-305 or M-14 or M-14S ] as only a stripped FORGED receiver, with very close to US GI dimensional specifications, you can never go wrong. Think of all those extra parts that come attached to the receiver as [ mostly usable ] free bonuses. If you like a hands on, do it yourself project, get a Chinese M-14 Simply do a bit of tuning, add the requisite US GI parts, and you have one of the best rifles available, and at only 1/3 or so of the cost of an equivalent Springfield M1A.
BUT,
for those who don't want to get their hands dirty working on their own rifles, or who don’t want to pay for a gunsmith to do it for them, the Springfield M1A can be a very good choice. Springfield offers a lifetime warranty on the M1A. Unfortunately, this lifetime warranty may be required even on a brand new Springfield, because, in my experience [ and in many other M1A owner’s experience ] there may not be much difference in quality control between the new US and the new Chinese made versions, There have been considerable complaints that many of the M1A CAST receivers are not correct dimensionally. Aside from the CAST receiver, new Springfield M1A rifles no longer use surplus US GI internal parts, and in their place, SA has turned to more cast parts, of varying quality, from various suppliers.
Known Springfield Armory M1A deficiencies
Springfield Armory, Inc. M1A rifles may have some or all of the following deficiencies:
1) The receiver scope mounting hole and mount surfaces may be out of specification, which makes fitting non-adjustable scope mounts difficult.
2.) The receiver bridge primary (bolt closing) firing pin retracting surface can be mislocated. The camming surface of the tang on the firing pin should be inspected carefully for damage. If the firing pin tang is damaged, the firing pin should be replaced with a non-chromed firing pin. With firing pins that are not chromium plated, most of the damage will be on the firing pin instead of the receiver bridge. The harder surface of the chromium plated firing pin will cut a groove into the receiver bridge deeper and sooner .. Note that light polish wear is normal on the retracting surface but a groove cut into the receiver by the firing pin is not.
3) The bolt may be cast, and have cast parts. These cast bolts are not top quality, and especially have a bad habit of losing the cast extractor
4) The receiver locking lug engagement surface is slightly misaligned. Lapping the bolt to the receiver can resolve this, and is recommended to evenly distributes stress on the receiver.
5) The bottom of the bolt roller makes contact with the receiver when the bolt is in battery, preventing the bolt from closing completely. The fix is to grind a half round relief cut into the receiver, to accept the bolt roller when fully locked in the down position. This will save replacing the bolt or bolt roller, which otherwise could be destroyed rather quickly.
6) The receiver groove that takes the tab of the op rod may be undersize, rough, vary in size, and not cut straight. This can cause rough functioning, unreliability, quick wear on that tiny op rod tab, and op rods eventually jumping out of the track. This also can cause extra work when properly fitting a replacement GI or Chinese op rod with an unworn, full size tab.
7.) The receiver rear sight elevation knob indexing detents wear prematurely due to too soft surface hardness. The fix is to install an elevation repair disk.
8.) The holes for the bolt lock pin are too small. The bolt lock roll pins could be forced in which may cause one of the bolt lock window receptors to break. The simple solution is to use a slightly smaller diameter pin.
9.) Some of the earlier Stainless Steel barreled “loaded” rifles, had the chambers cut TOO FAST = very rough = reamer chatter = poor extraction and reliability.
10.) The rear sight pocket is slightly too short. This results in a slight over hang of the rear sight base at the rear.. This springs the rear sight cover more than it should. The front edge of the cover can be lightly filed down, which requires less force to install the rear sight cover.
NEW Chinese M-14 rifles VS OLD Chinese M-14S or M305
I make a distinction between the OLD Chinese M-14 rifles, Polytech and Norinco, and the NEW Chinese M-14 rifles. The OLD Chinese M-14 clones came in to Canada and the US before the US assault rifle ban. The NEW Chinese M-14 clones are all Norinco, and over the years, these have arrived in Canada in various batches … most recently Nov 2007. These NEW 14s are slightly different and potentially better than the OLD. However, Chinese quality control varies considerably amongst individual rifles. Some of the old Chinese M-14 rifles were as good as it gets right out of the box, and can give years of safe, reliable service. Unfortunately, some of the Chinese M-14 rifles, new or old, can become unsafe to fire within a few hundred rounds.
To me, the most significant difference between the NEW and the OLD Chinese M-14 rifles is that the NEW batch of Norincos will take a “drop in” GI bolt. This was definitely NOT the case for the older Chinese M-14 rifles, Polytech and Norinco alike. On most of the old ones, the barrel hood protruded into the receiver about .010” too much, so that a GI bolt would require massive amounts of lapping in to fit up properly. So, for these Chinese M-14 type rifles, you usually needed to swap in a GI barrel, or do other major modifications when swapping in a GI bolt.
The next important difference is that the NEW Chinese M-14 rifles all seem to have the flash hiders permanently attached. This matters primarily if you want to swap out or work on the gas assembly, and /or swap to different style flash hiders or compensators. Taking off a welded on flash hider is NOT a trivial job. Also, the NEW batch has the tiny barrel retaining screw MEGA-torqued down, then MEGA-STAKED in. Getting this screw out is again non-trivial.
Another consideration between the NEW and the OLD Chinese M-14 rifles is that the NEW batch of Norinco's, in some cases, MAY have significantly improved quality control. I say “MAY”, because, while I have not seen any soft bolts recently, the bolts may still be fitted improperly, and may have way too much headspace. Also, on a sad new note, while I never saw a major misalignment of the barrel / receiver in the OLD models, this misalignment[ aka misindexing ] is epidemic with the NEW NORCs.
Known Chinese Norinco / Polytech M-14 / M-14S / M-305 deficiencies
First thing to understand about the Chinese M-14 clones, whatever manufacturer, and whenever they were made, is that Chinese quality control varies considerably amongst individual rifles.
While the Chinese FORGED receivers are usually closer to US GI dimensional specifications than most commercial receivers, with the Chinese M-14 clones, heat treatment and quality control during assembly of the fitted parts may vary considerably.
In my personal sampling [ several dozens ] careful inspections have found MOST [ about 2/3 ] of the Chinese M-14 rifles to be good to excellent overall, or else they could be made into great rifles with a bit of effort, and some US GI parts. I have also found a few receivers that were a bit softer than desirable, but these would still make safe and reliable shooters … they just might wear out a bit earlier. I also found one Chinese M-14 receiver that was heat treated too hard [ as in BRITTLE ]. This one was unfired, sold as a stripped receiver only, and it shattered while being fitted with a barrel. This was fortunate, as a receiver that is too hard is much more unsafe than one that is too soft, and without proper test equipment, is very difficult to detect.
This is why it is so important that the end user has as much knowledge as possible when buying any M-14 type rifle. A careful inspection can determine if you are getting a silk purse, perfect as is, or a sow’s ear, that will require lots of money and labor to get right.
1) Even brand new, the original Chinese bolt may be poorly fitted at the left locking lug, the bolt may be too soft, headspace may be grossly long for SAAMI .308 Winchester specifications even though the firearm is marked as .308 Winchester, headspace will almost definitely be too long for reloads using .308 Win brass, and bolt timing may be incorrect. … or all of the above.
Most of the NEW Norinco clones I've checked recently had about .009” - .013" headspace over 7.62 NATO GO. When you consider that SAAMI .308 Win NO GO is approximately equivalent to 7.62 NATO GO, you can see that if shooting .308 Win ammo in these lengthy chambers, the SAAMI THEORETICAL safety margins are being exceeded by quite a bit. That being said, in the real world, my personal Chinese M-14, new out of the box, had .009” headspace over 7.62 NATO GO. This particular rifle also shot a sub-moa group out of the box with factory loaded .308 Win 168 Gr HPBT match ammo. Here in Canada, we have thousands of these M-14 type rifles floating around with similar or even worse headspace measurements, and have very few [ or none? ] documented cases of too long M-14 headspace causing case separations with NEW commercial .308 factory loaded ammo.
If you want to reload for the M-14 rifles, or if you want target accuracy, or if you want that extra theoretical safety margin that tighter headspace can give you with .308 Win commercial ammo, then in most cases, the fix is relatively simple [ if a bit expensive ] … just replace the Chinese bolt with a US GI M-14 bolt. In most cases, with Chinese receivers and barrels in good condition, this takes only a few minutes of lapping in before almost perfect .308 Win GO headspace is achieved.
2.) The barrel may be incorrectly indexed to the receiver . If the front sight leans to the left, and the rear sight is adjusted to the right to compensate, then the barrel has been over-tightened. To correct this, the barrel must be removed, and the barrel shoulder must be rolled back to remove the metal distorted by this over-tightening. Since proper alignment, torque, and fit of the barrel shoulder to the receiver is critical to accuracy, this is not a trivial fix.
If the front sight leans to the right, and the rear sight is adjusted to the left to compensate, then the barrel is under-tightened. This is not as serious as over-tightening, as in most cases all that is required is to remove the little lock screw under the op rod at the receiver/barrel, and using the proper tools and torque specifications, tighten / rotate the barrel to the proper location. This is what is known as “INDEXING” the barrel
3) The Chinese op rod spring is undersize in diameter, and usually will not last as long as a US GI spring. Replacement with a US GI spring, even a well used GI spring, is the very first upgrade any Chinese M-14 owner should consider. NOTE: the Chinese op rod springs are smaller in inside diameter than the US GI springs. If fitting a US GI spring sized round style op rod spring guide, the Chinese springs may bind and cause reliability issues.
4) The hammer, trigger and sear, may be soft, and also may require a lot of fitting to get a safe trigger, with no creep, and a decent pull weight. The trigger pin and the hammer pin, as well as being soft, may also be undersize. An undersize pin that wears out of round quickly, does not contribute to a good trigger pull.
5.) The Chinese wood stock is made of mystery wood … some are as soft as balsa. This wood will compress under tension, or may swell when wet, and the result may be a trigger mechanism that is unsafe = the hammer will follow the bolt down if the trigger is held back during cycling, or also have an effect on fit when latching in magazines.
6.) The Chinese rear sight mechanism may be soft, and wear quickly to the point where adjustments are not possible, or won’t stay set. Again, replacement with US GI parts will fix.
Recommended Chinese M-14 Modifications
Above the cost of a basic/box stock Chinese rifle [ approximately $ 450 – 475 Canadian after shipping/taxes ] the costs to do up a Chinese M-14 properly are approximately …
REQUIRED:
$ 75 - Gunsmith inspection to check headspace, bolt fit and other issues.
$ 10 – US GI op rod spring
OPTIONAL [ in order of importance ]:
$ 75 – reindexing barrel [ if required ]
$ 130 – US GI Fiberglass stock
$ 20 - long op rod guide retaining pin [ or modify GI stock for short pin ]
$ 45 - SS one piece round/match op Rod spring guide
$ 50 – trigger job with stock Chinese parts
$ 80 – replacement US GI rear sight, M-14 or M1 Garand
$ 300 – US GI Bolt [ usually required for use with .308 commercial ammo ]
NOTE: some of the OLD Chinese will NOT take a GI bolt without also using a GI barrel
$ 250 – US GI Barrel
$ 40 ea - MAGS 20/5 - Chinese or $ 80 ea - USGI MAGS
$ 60 - US GI Hammer, trigger, and pins
After that, the sky is the limit.
Shorty / Bush / SOCOM estimate
Additional costs to do up a shorty are approximately :
$ 75 - shortening barrel
$ 75 - threading muzzle for flash hider and installing AR 15 type FH
$ 85 - front sight that fits on the gas assembly [ Gas Ring Front Sight ] NOTE: the gas lock threads are METRIC on the Chinese barrels, so a METRIC GRFS is required
7.62 NATO VS .308 Win
As a GROSS GENERALIZATION for newly manufactured ammunition, the variations in external cartridge dimensions between .308 Win and 7.62 NATO cases are not that significant. Ammunition from different manufacturers, between lots of ammo from the same manufacturer, and between individual rounds within a lot, may be greater than any theoretical differences in external dimensions between 7.62 NATO and .308 Win ammunition. However, there are other very significant differences between the two types of ammunition. One such difference is that 7.62 NATO brass is usually thicker, especially at the base. Also, the brass in 7.62 NATO cases generally seems to be tougher, perhaps drawn of a stronger alloy. This thicker 7.62 brass results in smaller internal volume with 7.62 cases, so load data and reloading data is NOT interchangeable between 7.62 NATO and .308 Winchester. In semi auto rifles, the tougher / thicker 7.62 NATO brass is better both for initial firing, and for potential reloading.
7.62 NATO military ammunition is carefully chosen to optimize performance in 7.62 NATO gas operated military rifles, like the M-14. This restricts the choices in internal and external ballistics considerably. On the other hand, .308 Winchester ammunition is designed for sporting or target use, with a wide range of intended targets, available in many bullet weights and bullet types, from many different manufactures. The really significant differences between 7.62 NATO and .308 Win ammunition may not be readily apparent, but they ARE there. Just as an example, 7.62 NATO ammunition may be loaded to higher pressures than SAAMI spec .308 Win. Bullet weights and pressure curves for 7.62 NATO take into account the inherent characteristics of a gas operated rifle, while commercial loaded .308 Win may not. Differences such as bullet weight, powder choices, retardant for the powder, Berdan or Boxer primer, crimped in primer, sealant at primer and bullet neck, crimped bullet, bullet weight, and bullet type, can all have a significant effect on safety, reliability, accuracy, and durability.
Headspace AKA … can I shoot .308 Win commercial ammo in my Chinese M-14S … after all it is marked .308 on the receiver?
Most .308 Win ammunition will function safely in a M-14 type rifle, if that rifle has .308 Win headspace. Headspace varies considerably with the M-14, clones or originals. The headspace of your individual M-14 type rifle will be the major consideration when determining if .308 will shoot safely. Most likely, the answer will be a qualified ... MAYBE?
If you stray too far from 7.62 NATO standards regarding bullet weight and pressure, you can get into durability, reliability, and accuracy issues. The M-14 was designed for 150 gr bullets, with military powders tailored to have the correct pressure characteristics at the gas port. The twist in the M-14 barrels likes 168 gr bullets for excellent accuracy. Those who choose heavier bullets at high velocity, for hunting or for long range target shooting, will have to be aware that recoil from these heavier bullets can do significant damage to the M-14 rifle. Those who go too light, either in bullets or in powder, may find the gas left over at the port may not have enough power to operate the mechanism reliably and consistently. That being said, I have tested a few M-14 rifles with the sabot loaded Remington .223 55 Gr Accelerators, and this makes for a reliable shooting load, with no recoil, that may be accurate in your individual M-14. As usual, with individual opinions and experience, your personal mileage may vary.
The M-14 rifle is incredibly sensitive to variations in ammunition, and some loads may shoot MOA out of your individual rifle, while others are closer to hour of angle. Best advice I can give on ammunition, is to try as many different brands, weights, and types of ammo, 7.62 NATO Ball and .308 Winchester, to find what your individual rifle likes. Then buy a case of it.
How do I measure the headspace of my M-14? AKA Headspace gages:
Measuring the headspace on an M-14 rifle is NOT rocket science, but it can be a bit complicated, especially if you don’t have all the proper tools and gauges, and know how to use them.
Forster Winchester .308 GO: 1.630"
Military # 7274780B GI "GAGE HEADSPACE" for 7.62 NATO GO: 1.6355"
NOTE: the .0055" extra of the military 7.62 GO is .0015" over the .308 Win NO GO of 1.634"
Also, the GI gage is cut out at the back for the ejector ... to allow you to measure headspace without taking the M-14 bolt apart.
NOTE: the commercial .308 Win gages are NOT cut out for the M-14 ejector, which is spring loaded with enough power to launch it clear across your living room into the darkest corner, and into the deepest part of your shag rug. This incredible spring tension will bear directly on any gage that is not relieved for the ejector, and trying to measure headspace when the gage is being forced into the chamber, and the bolt is being forced into the receiver, is not …repeat NOT …accurate. If you are using a commercial gage that is not relieved for the ejector on an M-14, then you MUST strip the bolt first before trying to measure the headspace
I have both .308 and Mil Spec 7.62 GO gauges, and find I really don’t need any more. With a set of feeler gauges, I can get quick and easy headspace estimates, from zero on up to very scary. This method uses the gage and the feelers to measures only the dimensions of the gap between the right side of the receiver, and the right bolt lug. If the bolt is straight, and if the wear pattern on the bolt lugs shows that the bolt is bearing evenly on both sides, then and only then, you can extrapolate that the left lug has the same gap dimension. If you want more precise measurements, without resorting to a {VERY EXPENSIVE ] set of custom gauges in .001” increments, you can make a set of spacers by cutting up a cheap set of automotive feeler gauges. Stack them up on your GO gauge, using thin grease to hold them together, and you will have as close to a perfect measurement as you can get, without resorting to expensive tools.
What should the headspace be on an M-14 type rifle?
For rack grade M-14 rifles7.62 NATO GO is 1.6355” [ very close to .308 NO GO ]
7.62 NATO Field Reject is either , DEPENDING ON SOURCE., 1.6415” or 1.6445,
NOTE, however, that the overhaul procedure for rack grade M-14 rifles specified -
“ … to maximize barrel life (with 7.62 x 51 mm NATO ammunition)
every effort should be made to keep maximum headspace no more than 1.6375 ".
M-14 National Match headspace standards are as follows:
GO 1.633"
NO GO 1.636"
NOTE: These recommendations are for US GI 7.62X51 NATO mil spec ammunition in a CAREFULLY cleaned and maintained match rifle
MAXIMUM Headspace:
When it comes to "real world" headspace, relying on headspace gages alone can provide only a precise measurement of chamber length. The other part of the equation is ammunition dimensions. So, unless you measure brass before and after firing, even in best case scenarios using a gage to measure headspace is always going to be a "best guesstimate
.308 Win "SAAMI" FIELD REJECT is 1.638". Although I have never personally seen it or read of a documented case, in theory, some commercial .308 Win cartridge cases may fail with a case separation on the first firing at .308 NO GO.
If your headspace is 1.638" - 1.6445", you should use only 7.62x51 NATO mil spec ammo.
If your headspace is 1.6445" or longer, even with mil spec7.62 NATO ammunition,
the chamber may be too long for safe use .
MINIMUM Headspace:
Chambers which are too tight may actually be detrimental to accuracy, reliability and safety. Also, semi auto rifles with tight chambers will require more cleaning to be reliable and or safe. If your headspace is less than 1.632", you may find the chamber too tight with some brands of .308 Win or 7.62NATO ammo. With short chamber, the case neck might be squeezed, or the bullet might be pushed back by the lands, both of which can disrupt accuracy and up pressure. Plus, with the M-14 "floating "firing pin, short chambers can increase the risk of “slam fires" especially with soft commercial primers. Finally, reloading ammo for a tight chamber may require small base dies, case trimming, and immaculate case preparation.
When fitting M-14 headspace for new "Match" rifles, I first lap the bolt in for proper maximum contact. Then I try for 1.632" headspace [ Forster .308 Win GO gage + .002" shim cut from a feeler gage, bolt stripped to ensure ejector tension does not push gage forward ]. This measurement is usually capable of turning a STRIPPED bolt all the way down easily on most brands of NEW FACTORY .308 or 7.62 NATO ammunition. The test cartridge should fall easily out of the chamber, and there should NOT be any major marks or deformation. Remember, you are not trying to resize the cartridge with the rifle.
Bolt to Receiver Fit …. What is the left lug doing?
From a safety perspective, bolt lug to receiver fit can be much more critical than headspace. With the M-14 rifle, headspace is only one part of the bolt fit equation. Far too many Chinese M-14 rifles, new and old, and even some brand new M1A rifles, have the left bolt lug cut or fitted improperly. If the left bolt locking lug shows signs of being hand ground by a Dremel like implement, the possibility exists that are you are shooting with only the right locking lug engaging properly. This is much more important than a few thou headspace, but even here, most of these bolts don't cause safety problems UNLESS they are also very soft. If you also have a soft bolt with a left locking lug that is cut at too acute an angle, then in a few hundred rounds the left lug peens back, the bolt face gets cocked excess headspace can get very scary . BTDT … seen several of the OLD Chinese M-14 bolts like this.
With the M-14, which has a very tiny and complicated left locking lug design, the bolt should be bearing EVENLY on BOTH lugs, and the bearing should be maximum. … especially at that awkward left lug. This is easily seen on a used M-14 type rifle by checking the wear patterns on the bolt lugs. On a new bolt, the way to check fit is to clean and dry the lugs in both bolt and receiver, and use a permanent felt pen [ RED is nice ] to mark the bolt lugs. With slight rearward tension, work the bolt up and down a few dozen times, remove the bolt, and inspect the wear pattern scraped out of the red ink. What you are looking for is EVEN wear on the locking lugs, with MAXIMUM bearing on BOTH lugs
This well known and too common defect in clone M-14 rifles, is why a USGI bolt swap is such a great idea. USGI bolts go for about $ 300 these days, and a $300 upgrade to a $399 Chinese rifle may not make much sense ... until you consider that with a few minutes work lapping the bolt to the receiver, and a few other bits, you can end up with a Chinese / US GI crossbreed that is totally reliable, and as good a shooter as a Springfield M1A that costs several times as much. And that brand new expensive M1A might still need a new GI bolt to replace a cast bolt.
PS: Not all the OLD Chinese M-14 clones have this problem … I would estimate only about 1 in 3. Recently I picked up an old Chinese M-14S at a gun show. It was ancient, stored 20 years or more, but it was almost unfired. Checking the fit of the original Chinese bolt showed almost perfect bolt lug mating to receiver, and headspace was .308 GO plus .002", which is PERFECT!!
Detailed inspection … front to back
1.) Flashider: Is it welded on? Is it loose? Is the castle nut on tight and locked in place by the set screw? Is the set screw loose.? Is the FH on straight? Can you see any indications that bullets are hitting the FH? Has it been reamed to NM specs? Is it cast? Is it cracked? Is it pitted and corroded? Does it have a bayonet lug? Does it have slots, or is it completely closed? Does the rifle “sing” when the bolt slams forward on an empty chamber?
2.) Front sight: is it straight = vertical or is it rotated to one side or the other, indicating expensive reindexing? Is it loose? Is the square at the top? Is it set way off to one side? Is the sight retaining set screw there? Is it the narrower NM sight?
3.) Barrel: is it bent? Is it tight to the receiver? Is the op rod guide tight? Is the op rod guide aligned correctly so the op rod meets the gas piston center? Is the bore chromed? Pitted? Is the chamber smooth … or are there reaming marks visible?
4.) Gas Assembly: is it loose = rotation? Slides back and forth? Is it misaligned? Is the gas assembly plug tight? Does the gas assembly line up with the hole in the barrel? Is the gas turn off valve vertical or horizontal? Is the bore of the gas assembly corroded or worn? Does the piston move freely and smoothly? Is the piston chipped or peened? Is there carbon built up inside the gas assembly or the piston? Does the ferrule rattle? Does the hand guard ferrule tension correctly to the stock?
5.) Op rod: Chinese op rods are forged one piece, same as the best US GI TRW op rods. Chinese op rods are usually good for hardness. Check for tab wear, bends, and cracking? Springfield op rods are often US GI, but if not, they may be cast, and vary considerably in quality. US GI op rods are, of course , the best, but most are now well worn, and rewelds from scrap pieces may be on the market. Check the weld on any two piece US GI op rods for cracks and voids. Check for bends, and that the op rod runs straight in the receiver groove?
6.) Receiver: Field test check for softness … run a file lightly over some hidden spot see if file catches and cuts easily … if so, this receiver is too soft for long term durability. Reheat treatment may be desirable. Look for any obvious burrs, cracks, or rough spots? Some of the NEW Chinese receivers have the top of the receiver right locking lug corner cut square [ and sharp enough to cut yourself ]. This corner should provide a smooth transition between vertical to horizontal motion, and should be softly rounded and smooth. Some of the OLD Springfield Armory M1A receivers do NOT have enough clearance under the bolt roller, to allow the bolt to close completely. This will slam the bolt roller between the receiver and the op rod … which is not a good thing. Simple solution for the sharp right lug corner, and no bolt roller clearance … a Dremel with a ½” wheel. Also check at the rear, where the tang of the safety rotates against the receiver … is there a groove worn into the receiver by the tang?
Other than the above, checking the receiver for proper dimension is a job for a professional with the right tools. However, every Chinese receiver I’ve personally inspected was as good or close to US GI dimensions. Odds of you getting a bad Chinese receiver are very slim. If this is a cast commercial receiver, odds of getting some dimensional variations are very high. Whether these variations will significantly effect performance is again best left to a professional to determine. As an example, with the last Springfield M1A receiver I built up into a full house target rifle, the bolt lapping with a NEW GI TRW bolt took about 30 minutes to achieve proper bearing on both lugs. It also took about 3 hours to fit a near new TRW one piece op rod. The final product was as good as it gets, but it did take a LOT longer to fit the GI parts, than would be usual with a Chinese FORGED receiver.
7.) BOLT: inspect the left locking lug … does it look like it was hand ground with a Dremel tool? If so it may not be properly fitted to the left locking lug. On a used bolt, check the wear patterns. On a new bolt, get some RED permanent marker ink on the lug surfaces, and inspect the seating. Does the bolt engagement provide maximum bearing evenly on both lugs? Extractor fit? Ejector spring tension? Firing pin protrusion? Timing? firing pin tang wear ?
Test fire … go to the range and load only two rounds in the magazine … test fire one round … see if the rifle doubles? eject the second round from the chamber and look at the primer dimpling? … yes, the M-14 has a floating firing pin, with no spring to keep it away from the primers. Yes, this is scary, but on a properly set up M-14, using proper ammunition, you will not get a slam fire.
At the last WET Coast M-14 seminar, we had one bolt that had a bit of brass stuck in the firing pin hole. This is not that uncommon with these rifles, especially if the firing pin hole is worn, or the pin tip is chipped. PAY ATTENTION HERE ... this is definitely not a good thing [ aka "INSTANT DEATH or SLAMFIRE" ].
Because the firing pin is the inertial design, with NO RETACTING SPRING, it is a very good idea to check that firing pin hole from time to time, to see if any crud [ especially primer shavings ] is building up in there. While the firing pin/receiver camming action SHOULD still retract the firing pin even with a bit of garbage clogging the system, this is not something you want to test for your self. A clean rifle is a happy rifle ... and a lot safer too.
Which leads to the scary question ... how do you take that bolt apart??? There are enough horror stories about M-14 bolt dissambly [ that ejector spring launches the ejector with enough power to pierce your eyeball and embed itself in your brain ...yadayadyada ] that it might pay to invest in one of the bolt disassembly tools. The tool makes it simple to disaasemble the inside gubbins, and keep the firing pin channel clean.
8.) Rear Sight: Is the rear sight tight, or does it move around a lot if you wiggle the aperture arm? Is the hole in the rear sight centered? Does the rear sight move up and down? Does the rear sight adjust left to right? Does the sight stay set ?
9.) Trigger group: does the trigger group lock in with a bit of spring [ about ½” of tension ]? Does the safety lock the firing mechanism when engaged? Does the safety move with correct tension? With no magazine in the rifle, hammer cocked, and safety on, does the hammer follow if you drop the bolt on an empty chamber? Try this again with the safety off to test the front hooks on the hammer? Now, with the trigger held back, test the rear hooks on the hammer by trying this again? Is the trigger pull creepy? What is the weight of the trigger pull? Measure it carefully …4 and 1/2 lbs is the MINIMUM safe weight. If it is less than 4 ½ lbs, then the hammer may follow in some circumstances. … especially if the rifle is not held tightly against the shoulder.
NOTE: changing stocks on the M-14 rifle can definitely change the way the trigger functions, so every time you swap the stock on an M-14 type rifle, you should do this trigger group safety check again.
.At the range, after performing test firing for test # 7, load five rounds … hold the rifle loosely … and fire all five rounds. With the rifle held loosely, did it double … or worse yet, run away with the whole magazine?
10.) Magazine: Pinned correctly to meet Candian firearms laws to 5 rds ONLY? Latches in the receiver tightly? Bent lips? Dents? Follower? Spring?
11.) Stock: Is the receiver tight to the bedding lugs? Receiver tight at top rear bedding surface? Does the receiver slide back and forth in the stock? Are the bearing surfaces for the trigger guard compressed in? Does the trigger guard lock in with correct tension? Is the front of stock tight against the ferrule? Ferrule greased? Hand guard cracked? Loose? Clearances at top of fore stock? Butt plate bent? If using a GI stock with a clone, has the connector lock pin been replaced with a longer one, or has the stock been padded to keep the shorter commercial connector lock from shuffling out? If using a Fiberglass GI stock, does the butt plate have the correct top screw, nut and nut retainer?
12.) Accessories: did you get a complete cleaning kit? Have you looked in the butt trap? Did you get a sling? Bayonet? Spare Magaziness?
13.) Scope mount … is this one of the very few gawdawfulexpensive scope mounts recommended by the CGN scope mount FAQs that will actually work, or is it cheap no name TRASH??? If you paid a lot less for it than you did for the rifle, then it is most likely TRASH. If you can shoot better with Iron sights than you can with a scope, then your scope mount is loose … and is probably TRASH.
PS: did you get the message yet … there are a lot of scope mounts out there for the M-14, but most of them are TRASH..
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