Future M305 owner

fellers88

fellers88

Regular
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Location
Kelowna, BC
Hey everyone im fairly new to this site and definately new to the M14 community. I just put in my order for a regular length m305 from CanAmmo and I am still trying to get as much information I might need before a start to accurize it. After I take it to the range and figure our how it shoots before doing anything to it, I figure Ill shim the gas system and replace spring guide and spring before anything else.

After that i guess i would be looking for input on what to do next. Whether it would be trying to bed the stock or replacing any other parts afterwards

Have any of you guys bedded your stocks and had any real success with it? And how did you go about it?

I guess my final goal would be to throw a scope on it and queeze as much accuracy as i can out of it, but dont get me wrong im not trying to attain quarter MOA groups with this set up.

And after doing some poking around I have noticed some talk about using either .308 or 7.62 NATO, and different people have said that different M305s say to use different ammunition. So has everyone checked the headspace for their rifles and used whatever ammo is closest? Which leads me to... if my rifle best opperates with NATO, how do I handload to those specs or how do I change my rifle to .308 (whichever is easier)

Thanks for your help I know its a lot of questions in one post
 
I'd say the single biggest thing you could do to increase accuracy in any rifle, not just the M-14, is to start handloading for it. Granted, your idea of replacing the spring-guide is a great second step. My groups shrunk about 1" after I played around with different bullets and powders. Currently, she's a 2.5" shooter without any additional mods.
 
First, you should do a few things BEFORE you take it to the range:

-check to see the magazine will only hold 5 rounds, not more

-field strip the rifle (take appart into basic components), remove Cosmoline preservative

-grease the specific areas to grease (see the stickied notes on this subject)


There are a lot of ways to accurize these rifles, the first step should ALWAYS be to replace the op-rod spring guide. There's lots on the subject, but it's a cheap (mine was $35) and painless, no time expended way of improving the accuracy. Yes, bedding the stock does work on this rifle, it's detailed on at least a few places on the 'net.

This is a really accurate semi-auto rifle. But it's not a "sniper/precision" rifle, even with $10k into it. Keep that in mind before spending big bucks.

Ammo isn't cheap, typically around $1 a shot. It's not 9mm, 7.62x39 or rimfire!

Scoping this rifle DOES work if you do it right. But it seems like 2/3's of "M-14 M1A" scope mounts are utterly worthless JUNK at any price. You need to comb this forum for people talking about which scope mounts they have had success with, as many will fail to hold a zero, or just plain fail.

This rifle will handle .308 Winchester just fine. For GENERAL knowledge, it's basically the same thing as 7.62Nato. The critical part for the M1 Garand, Springfield M1A, and Chinese M-14's is the bullet weight: don't go above 168 grain bullets...it will wear out your rifle components prematurely, and possibly cause them to fail catastrophically.
 
Some parts need replacing (sight knobs IF you are an iron sight lover) but not everything needs to be replaced. Lots and lots here for you to read and get acquainted with. Have fun learning and discovering the M14 addiction!

Cheers,
Barney
 
RickR1100 said:
This rifle will handle .308 Winchester just fine. For GENERAL knowledge, it's basically the same thing as 7.62Nato. The critical part for the M1 Garand, Springfield M1A, and Chinese M-14's is the bullet weight: don't go above 168 grain bullets...it will wear out your rifle components prematurely, and possibly cause them to fail catastrophically.
Click to expand...

If you got it from canada ammo you should be ok for 308.

Some of the older chincos had problems with chamber sizes, if in doubt, check it out....

if you really want to know...m14forum

A little bit of everything to do with headspace.
Part I

Folks, I thought it might be a good idea to make one sticky about headspace that people can refer back to as needed, rather than having short posts strung all through the forum. So let’s start with what Headspace is and why it is important.

Having the correct headspace is a HUGE Safety Concern in all firearms and especially in center fire rifle cartridges because the pressures involved are much higher than other firearms. Both the M1 Garand and the M14 operate at 55,000 pounds of pressure at the breech. Nothing to sneeze at or mess around with and this is serious business.

MINIMUM HEADSPACE: This is the amount of room necessary to ensure the longest cartridge manufactured to correct specifications will fit and will have enough room to expand to seal the chamber. There has to be enough room for the cartridge case to expand so there isn’t too much pressure on the rifle. I personally fixed a DCM M1 Garand that had exceptionally short headspace. (Don’t know how it got out of the Arsenal that way, but they never finish reamed the chamber.) When fired, that rifle cracked stocks within two clips of ammo and the owner said it “kicked like a mule.” I’m sure it did. Fortunately, when he told me about it I got him to STOP shooting the rifle until I could correctly cut the minimum headspace. Had he continued to fire that rifle that way, the super high chamber pressures generated because the cartridge case didn’t have enough room to expand would have at least indented his receiver and bolt, besides continuing to damage stocks. It would also have caused the bolt and receiver to crack, chip or break had he continued to fire them and his rifle would have wound up as a pile of junk. You don’t want a chunk of metal from the receiver or bolt coming back into your eyes, even if you wear shooting glasses.


MAXIMUM HEADSPACE: This is the amount of room necessary so the shortest cartridge manufactured to correct specifications will fit and will have enough room to expand to seal the chamber without expanding so far that the cartridge case will expand until it ruptures or a piece of the cartridge case breaks off. When that happens, you are going to get a good deal of nasty and hot gas coming back into the action and towards your eyes. God Help you if you aren't wearing shooting glasses, as you could very likely suffer permanent eye damage. Much of the gas coming back normally blows the magazine base out the bottom of the magazine well and cracks and splinters the stock along the sides of the magazine well at least. That usually isn't life threatening, but you may wind up with some good sized chunks of stock in your supporting hand/arm. I've seen up close one real, G.I. M14 blow up and while it didn't come close to killing the Marine, it would have taken out his eyes had he not been wearing shooting glasses.

Military rifles often allow more of a minimum to maximum headspace length to take care of the variance of Mil Spec ammo and because the firearms will be fired in bad weather, will fill up with powder residue when fired a lot and/or where sand, mud and other “junk” can get into the chamber. The headspace is also more generous because military rifles are fired faster and with more rounds fired faster. That means the barrel will heat up and thus “close in” the headspace when the barrel gets hot. The heat expansion will the actually cause headspace to close up a bit when the barrel really heats up. So, there has to be a little more headspace room than in civilian rifles. EDITED TO ADD: Military spec. cartridge cases also have thicker brass to take the strain of larger headspace dimensions as well.

OK, so how is headspace measured? Well, that’s different for different types of cartridges, so let’s just stick to the M1 and M14 rifle because this thread is going to get long enough as it is. Grin. Headspace in these rifles is defined as the space or distance between the face of the bolt and to a point in the barrel chamber for the angled shoulder for the cartridge case. That point is called the datum point (or sometimes Datum line) in the chamber. Correct Headspace overall length and the datum point for these cartridges are specified in government specifications and/or The American Sporting Arms and Ammunition Manufacturers' Institute; hereafter mentioned by the common acronym of SAAMI and pronounced “sammy.” (A little more on this later.) The government arsenals had some very precise special adjustable gauges to check headspace, but even they usually used Headspace Gages that are precision ground to a precise length. Almost every civilian gunsmith or armorer uses individual Headspace Gages to inspect or chamber a rifle. So let’s go over the most common ones next.

The “ GO “ Gage: This is the shortest Headspace Gage and is used to check and ensure the chamber has the MINIMUM headspace necessary for reliable and safe operation for even the longest cartridge case that is still inside manufacturing specifications.

The “ NO GO “ Gage: This is the most widely MISUNDERSTOOD Headspace Gage and causes the most confusion to a whole lot of folks. I can’t tell you how many times I’ve heard or seen incorrect things said or written about this Gage and sometimes by people who SHOULD know better. This Gage is used by Arsenals or gunsmiths/armorers when they cut the Headspace in the chamber of a rifle along with the GO Gage. You have to cut the Headspace deep enough so the GO Gage will fit without showing additional friction on the bolt. That gives you the Minimum Required Headspace. You then use the NO GO Gage to ensure you don’t cut too much Headspace when you first chamber a rifle. Headspace may increase as much as one or two thousandths of an inch ( .001” to .002” ) during the entire life of the barrel until you shoot the lands out. SO you have to have a NO GO Gage to show you where to stop cutting and ensure there will not be too much Headspace throughout the entire life of the barrel. (IOW, when you stop cutting the headspace - there will still be a few thousandths of an inch before you hit the Maximum Headspace length.) The NO GO Gage is NOT the maximum gage and it is NOT the Gage that tells you the Headspace is too much or too deep. If you don’t cut Headspace, you really don’t even need this gage to check for safe Minimum and Maximum Headspace.

The “ Field Reject “ Gage: OK, THIS Headspace gage is the gage you use to check for Maximum Safe Headspace even when you get the shortest cartridge made to specifications. If the bolt closes on this gage without additional friction than before you had the Field Reject Gage in the chamber, then the barrel is UNSAFE and no one should fire the rifle until the barrel is pulled and a new one is installed. If one wishes to have the two necessary Gages to check Headspace, you need this Field Reject Gage and the GO Gage for any individual caliber.

There are going to be additional posts containing additional information. So please stay tuned. Grin.
Click to expand...

part II

Part II

OK, remember from the above post that Headspace Dimensions can be taken from both the U.S. Government Arsenals and/or SAAMI specifications? Before I go further I want to add that the dimensions might APPEAR to be different between them when you only look at the listed length dimensions. This is really important and caused quite a ruckus a few years ago when SAinc. started writing down the headspace on a tag they attached to the M1 Garand rifles they built with commercial receivers. The Headspace readings they wrote down were hugely different from the normal readings we see from Government Gages or from Gages made to Government specs. That FREAKED OUT a whole bunch of folks because they thought the barrels had been improperly cut for Headspace. When I first ran across this, I used my Government Gages that had been calibrated and found the SAinc. headspace was fine – as I figured it would be. SAinc. used gages that had the SAAMI spec reading on them and that’s why the readings were different.

SAAMI gages in .30-06 have a different length reading because they are measured to a different Datum line on the angled shoulder of the gage. The angle is different than G.I. gages, BUT that doesn’t mean a problem, it merely means the Datum Point is in a different area on the gage. Since chamber reamers are also standardized, the chambers are going to be cut close to the same no matter who makes the reamer. Not everyone has run across this or may have even heard about it, so I thought it was important to mention this as it may be something someone might run into on a M1 Garand or even a M14. I’m not sure if SAAMI length readings are different for .308/7.62mm and never saw them listed differently than how the government gages were listed, but if you run across this, just check them with regular gages and know the rifles will be fine when they pass headspace inspection with regular Gages.

Now it’s time to switch to another widely held misconception or myth about headspace on both M14’s and M1 Garands that are chambered in .308 or 7.62mm. These two calibers are pretty close to being the same with the main difference being the angle of the shoulder of the cartridge case, BUT they are NOT the same caliber. 7.62mm Nato ammo also has a slightly longer throat dimension than .308 Win.

Headspace lengths for caliber .308 Winchester

1.630" GO
1.634" NO GO
1.638" FIELD REJECT

The G.I. Headspace Gage lengths for 7.62mm

Go Gage...................................... 1.6355"
NO Go Gage................................ 1.6375"
Rebuild Maximum Gage.............. 1.6415"
Field Reject Gage....................... 1.6455"

NOTE: The information on Government Headspace Gage lengths was taken directly from the 3-5 Tech Manual and the Rebuild Standards manual published by Rock Island Arsenal.

Also, I would like to explain that "Rebuild Maximum Gage" reading of 1.6415". That is MY descriptive term for it because the Rock Island Arsenal Rebuild standards just list it as one of the three gages (by length) to be used for rebuild of real, G.I. M14's. Remember that Headspace should only grow at most one to two thousandths of an inch during the entire life of a barrel? If it goes much beyond that, you have a REAL problem with either the bolt or the receiver, or both. So, when they rebuilt rifles to 5th Echelon - Depot Repair Standards, they used 1.6415" as the maximum to ENSURE the barrel would not have a headspace problem during the entire life of a barrel. That “Rebuild Maximum Gage” ensures there is at least THREE thousandths of an inch less than the Field Reject of 1.6445", so there would almost never be a problem with Maximum Safe Headspace while the barrel was still good.

When we chambered (cut the Headspace) on real, G.I. NM M14 barrels for competition shooting in the Marine Corps, we used .308 Headspace Gages and chamber reamers. We used both NM G.I. Government “White Box” 7.62mm ammo and a proprietary Federal “NM type” .308 loaded ammo that has come to be called “Federal Gold Medal Match” in recent years. Everyone who doesn’t know should understand that NM ammo is loaded about 200 FPS LOWER and doesn’t develop quite as much chamber pressure as regular 7.62mm Nato ammo. Some NM Armorers in the Marine Corps (as well as some of the other Armed Forces NM Armorers) didn’t understand back in the early 1970’s that you can’t cut the chamber dimensions to a Minimum .308 Win. Headspace length and have both types of ammo perform properly in a Gas Operated Rifle. You can often, if not usually get away with it in a Bolt Action rifle, but NOT a “Gas Gun” as we called the M14. The reason for that is when you reload for a Bolt Gun, you only have to resize the neck. The expanded fired case will still chamber well in a Bolt Gun because of the mechanical advantage of the bolt action RAMMING the cartridge in the chamber. In a Gas Gun when you reload, you HAVE to resize the whole cartridge case or it won’t feed properly and will often get stuck in some chambers before the cartridge is fully seated. So in the real world, what did we find you have to do to chamber an M14 with NM 7.62mm ammo?

At first, we chambered NM M14’s pretty much the same way that NM M1903 rifles and other NM Bolt Action rifles had been chambered for decades. We chambered them as close to the minimum .308 Headspace length of 1.630” as possible. We also used Elliot Headspace Reamers that were absolutely the Ultimate Quality reamers in the 60’s and 70’s. These reamers were on the “tight side” of manufacturing tolerances. (Today, Clymer’s .308 Match Reamer gives a similarly tight NM chamber.) The Lake City, “White Box,” NM 7.62mm ammo in both 168 grain and 173 grain bullet loadings would function OK in most rifles, but not in all of them and not as accurately as we thought they should have with so tight of a chamber. We found that the rifles performed better and more accurately when chambered to between 1.631” and 1.633” when using NM 7.62mm ammo. Why was that? Well, look up above at the minimum chamber length for a 7.62mm GO Gage. That reading is 1.6335” for Nato Spec Ammo. We actually found it was better to ream Headspace a bit deeper before the answer hit us in a “No Scheit Sherlock” moment. What we did by lengthening the Headspace was to get it close to or right at the minimum 7.62mm chamber length even when using lower pressure NM ammo. So in the real world, it also shows up there is a difference between .308 and 7.62mm chambers. Well, that’s fine for NM or target grade barrels, but what about standard chambered rifle barrels?

Standard 7.62mm Nato ammo and ESPECIALLY foreign surplus ammo may or may not be held to true Nato specifications. One thing for sure is that standard 7.62mm ammo manufacturing specifications allows for a slightly longer cartridge case (and slightly longer neck) than .308 Winchester. Some Nato spec ammo like the really good Portugese 7.62mm Nato ammo is also a bit on the “hot” side of the 7.62mm range and that means slightly higher chamber pressures from the “Get Go.” So what does that mean in “the real world?”

If after reading all these posts on headspace you only remember two things, it is my most fervent hope you will remember these two things:

1. Do NOT use standard Nato Spec surplus ammo in a rifle chambered with a NM chamber and set up at the minimum headspace. Even if the rifle functions with no apparent problems, the chamber pressure of each round fired is significantly more than in a proper Nato Spec chamber. What you are doing is subjecting your bolt and receiver to more abuse and it will AT LEAST cause your bolt and receiver to wear out faster. If the cartridge case brass alloy of some of the questionable foreign surplus is used, you are also asking for cartridge case ruptures and gas and pieces of brass coming back into your face and possibly into your eyes.

2. If you are shooting 7.62mm ammo in a rifle chambered for .308 Winchester and the ammo does not feed and function properly and/or if the ammo has a greater “kick” or much louder noise than usual; PLEASE stop firing that ammo in your rifle. Now, this sounds like it should be a common sense reaction, but I have seen and heard of WAY too many people who continue to fire ammo that does these things. At a local range about 20 years ago, I was next to a guy who kept shooting some junk 7.62mm ammo is his M1A and about every 7th or 8th round wouldn’t chamber or he had trouble extracting the cartridge case. I warned him about the possible ramifications of firing that ammo, but he ignored the warnings. OK, I got up and moved all my stuff to the shooting bench the furthest away from him as I could and waited to shoot when he wasn’t shooting. He asked me why I moved and I told him I didn’t want to be close to that rifle when the cartridge case ruptured or his rifle broke and pieces of metal came flying off the rifle. He again ignored me and went back to shooting the rifle because, “I didn’t know what I was talking about.” Yep, he eventually ruined his bolt and receiver from firing that junk 7.62mm ammo, though fortunately in his case no one got hurt. God seems to sometimes protect even the worst idiots from their own bad actions at times.

OK, so CAN a rifle be chambered so that both .308 Winchester and GOOD 7.62mm Nato Ammo be fired in it without problems? The good news is yes it can. Most factories who make or fully assemble their rifles chamber them so you CAN shoot both, but it is not absolutely certain in every rifle and with every type of 7.62mm Nato Ammo. Please see Number 2. above.

Now, the GREAT thing is that if a rifle is chambered so that the bolt correctly closes on a 7.62mm GO gage at 1.6355" and does not close on either a 7.62mm NO GO gage of 1.6375" or the .308 Field Reject of 1.638" - then there are absolutely no worries about shooting either .308 nor 7.62mm in the rifle. This is how I chamber Garands and semi auto M14's for folks who want to shoot both .308 and 7.62mm surplus. (I chamber them so the bolt won't close around 1.635" to 1.636".)

If you use .308 Winchester Headspace gages, exclusively, you can still chamber the rifle correctly for 7.62mm as well. You want the bolt to just close without friction on the NO GO gage. That will ensure you have the minimum for 7.62mm and not too much headspace for the .308 at 1.638".

OK, that’s enough for this post. Stay tuned as more is coming folks. Grin.
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part III

Part III

Sooner or later this discussion leads to which Headspace Gages are “best,” so let’s take that next.

I mostly use Clymer Headspace Gages as I’ve had them calibrated by the Marine Corps Calibration Laboratory at Albany, GA and they ALWAYS came though calibration inspection with flying colors. I have also used and can recommend Manson, JGS, and Pacific gages. That’s it folks, there are no others I recommend.

What is SUPER important about Headspace Gages is that you stick to the EXACT SAME BRAND for each caliber. That means you buy the GO Gage, NO GO Gage and Field Reject Gage from the same company. If you don’t do that, you are going to get different or even wrong readings due to the different ways the makers manufacture the gages and their own tolerances - if you mix manufacturers in your gages.

If you aren’t going to do any chamber reaming/cutting, you only need the GO and Field Reject Gage for any caliber to make sure you have safe headspace. Some folks buy the NO GO gage just to give them an idea of how tight or loose the headspace is and there is nothing wrong with that, just understand you don’t need the NO GO Gage to tell you if the headspace is safe.

OK, someone out there has probably noticed I have not mentioned Forster Headspace Gages and is wondering why. Well, there is another story involving Headspace Gages, so I may as well relate it right now.

When I was transferred to Edson Range aboard Camp Pendleton, CA; among the RTE rifles there were NM bolt action Model 70 rifles in .30-06. They were one of the last Post and Station Teams that still had those rifles and they had kept them because they used them in the California Long Range Championships held at Marine Corps Base 29 Palms. Well, any rifle the Marine Corps uses HAS to be periodically given a technical inspection before it can be fired and that includes the use of Headspace Gages to inspect them.

One day my Gunner walked into my RTE Armory and was looking around. He liked the Model 70’s, but then he got a quizzical look on his face and asked me if I had a set of Headspace Gages to check those rifles. Well, I told him I had my own personal .30-06 Gages and used them. Then he told me he appreciated that, but when was the last time they were calibrated? OOOooops, well mine had never been calilbrated after they left the manufacturer. So, it was decided we should order two sets of .30-06 GO, NO GO and Field Reject gages and keep them as Team/Marine Corps property. We had to have two sets so one set would be in calibration and be used when we sent the other back for annual recalibration and vice versa. Note: In case anyone is wondering why we didn't order G.I. Headspace Gages for .30-06, they were no longer available through the Federal Supply System.

So, we dug out Brownell’s catalog and ordered two sets of Forster Gages because they were the least expensive. (Many folks start out buying Forster’s for that reason.) Then it took about a dozen phone calls till I found a Calibration Tech at Albany who assured me they could calibrate the gages even though they were not the G.I. pattern. GREAT ! ! So we packed up both sets of gages and sent them off. They told me they would have to work them into calibration cycle when they had slow time from other Infantry Weapons gages. No problem there. About three weeks later, I called to see how it was going and got some bad news. ALL of the six Forster gages FAILED calibration by a good deal. Awwwww………..crapola! That normally meant we would have to get another 6 gages. Fortunately, the Calibration Tech then told me they were all too long and they could most likely properly grind them down to size. Well, that worked on 5 of the six gages, but the sixth Gage was a Field Reject gage and it was just too short to regrind. So, we had to order another gage and that one was long enough, though too long as well and had to be reground.

I also got the Calibration Laboratory to calibrate a set of .308 Winchester Headspace gages that had been issued to me, but those were Clymer Gages. They passed calibration with flying colors. In the late 1980’s, Clymer Gages cost two or three bucks more each than Forster gages. A few bucks difference, BUT the Clymer gages passed calibration when the Forster gages failed. Sadly, a case of poor economy by trying to save a few bucks with the Forster gages.

When I returned to the RTE Shop at Quantico, they had not had their gages calibration inspected for a while, so I called my Calibration Tech at Albany and got half of our gages sent in. Once again the Clymer and this time the JGS gages we had passed and the Forster gages FAILED. Only about half our Forster gages could be reground so they would pass calibration. After that, I made sure we at the RTE Shop and when I personally bought my own gages, that we never bought Forster Gages again. I still have one .308 GO Forster gage, but it is almost as long as a NO GO gage. Since I know that, at times it comes in handy, though I DON'T use that gage to check Minimum Safe Headspace. I threw away my personal Forster .30-06 gages and other .308 gages because as a Armorer, I can’t use gages that will not meet or hold calibration due to liability concerns. That’s why I don’t recommend Forster gages.

One last thing on Headspace Gage brands and that is you don’t have to worry about using a chamber reamer from a different maker than your Headspace Gages. Since you are going to cut the chamber, it doesn’t make a difference who makes the reamer as you cut the chamber to size using your Headspace Gages. IOW, you can use a set of Clymer Headspace Gages and a JGS reamer and you will be just fine.

Yes folks, there is STILL more to come, so stay tuned
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First of all WELCOME to the addiction, your gonna have some fun :)

Second, this gun can be as expensive as you want it to be..............or you can avoid a lot of expense by leaving it well alone apart from stripping er down and rebuilding it PROPERLY. You get a huge improvement just by tightening the thing up..lots of stickies :)

Third.......if you ever get the chance go to one of Mr Hungry's clinics, there you will cover everything, and I mean EVERYTHING you will ever need to know about this gun.

Last of all its a pig to feed and groups will shrink when you get the right round for YOUR gun...and it eats cheap scopes........I know :)

Have fun :)
 
Awesome. All good stuff guys, cant wait till it shows up. So until I start hand loading, Ill be looking around for some cheap .308 to work the barrel in. Now i know CanAm has some Norc stuff that looks like the cheapest on the intrawebs but I wont be able to reuse the brass. Anything out there thats boxer primed thats a little less than a buck a shot?
 
Mine was a 2.5" grouper @ 100 yards with handloads. After a Hungry clinic, she'll do 1 & 1/8 inches @ 100 yards with handloads. Scoped both times both 5 shot groups.
 
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