303: Tried headspacing on shoulder, not rim?

[aletheuo]

Has anyone tried Parashooter's method of fireforming 303 british cases in your enfield that uses a spacer in front of the rim to fireform with?

Quoted from: http://parallaxscurioandrelicfirearmsforums.yuku.com/topic/3361/t/Headspace-101-for-303-s.html

Handloading

If you handload for a .303 with generous headspace, there's no need to mess with bolt heads - changing the rifle's clearances to yield longer case life. You can control head clearance simply by changing technique.

When you fire a new case for the first time, use an improvised spacer ahead of the rim - anything from a precision metal washer to dental floss can work to hold the the cartridge head firmly against the bolt face and eliminate or reduce stretch even if head clearance is significant. Another way of accomplishing the same end is to use a bullet seated out far enough to jam into the lands, "headspacing" on the bullet instead of the case. Such techniques are useful only if the rifle has excess headspace. With normal headspace, initial stretch isn't enough to worry about.

After you've fire-formed your new cases they will fill the chamber fully, stopping on the shoulder just like a rimless cartridge. If you neck size, you'll have zero "headspace". If you have to full length size, adjust the die so the cases chamber with just a bit of resistance in the last few degrees of bolt rotation.

Finally, don't try to turn a .303 into a magnum. Keep the pressures below the limit and you reduce the small amount the bolt and receiver compress/stretch on firing in a rear-locking action.

With these techniques you can make your .303 cases last for dozens of loading cycles, even if your "gauge headspace" is well beyond the .074" field spec.

Would like to try it - wondering what you found worked good for spacer material? Was thinking whipper snipper filament or even an o-ring of the right size?

 

[BUSHMAN79]

If you have a bunch of old primers and some Red Dot or similar powder, you can fireform brass to fit your chamber. Trouble with .303, some of the factory loads won't fireform properly. They are loaded so lightly that when the firing pin pushes the case forward, the primer just backs out to take up the slack. Using that spacer method would seem to be an easy way to avoid that problem. I would try small rubber bands, if you can find some small enough. Or maybe even scotch tape?

 

[Andy]

I haven't tried it with the 303 British, but I have with another rimmed round and it works - if the pressure is high enough. You need to be near max pressures, and subsequent to that, you need to only size the neck. There's not a lot of shoulder on a 303 Brit, so half efforts, and any sizing of the body to speak of, will not form enough shoulder to headspace on.

Me - I'd just buy the bolthead.

 

[aletheuo]

Me - I'd just buy the bolthead.

Yes, that was my initial thought as well, but if you read the whole article with pics in the link it becomes apparent that no matter the head spacing of your enfield you still will have quite short brass life because of headspacing on the rim and even the normal clearances. Paratrooper's experience and experimentation shows that rounds initially fireformed with the spacer (or jammed into the lands) can last as long as any other brass.

If he has figured a way to make 303 brass last three to five times the number of firings or more than usual then I'm in! This problem is the primary drawback to an enfield, IMHO, and if he's solved it then I'm hooked!

Anyone else tried it yet?

 

[Gary D]

I have heard that O-rings work great for this, but I haven't tried it myself. But then I have 6 303's at current and don't really want to have a unique set of brass for each one. Anyone working with the RCBS X dies in .303 to see if they extend case life?

 

[Andy]

Yes, that was my initial thought as well, but if you read the whole article with pics in the link it becomes apparent that no matter the head spacing of your enfield you still will have quite short brass life because of headspacing on the rim and even the normal clearances. Paratrooper's experience and experimentation shows that rounds initially fireformed with the spacer (or jammed into the lands) can last as long as any other brass.

If he has figured a way to make 303 brass last three to five times the number of firings or more than usual then I'm in! This problem is the primary drawback to an enfield, IMHO, and if he's solved it then I'm hooked!

Anyone else tried it yet?

All that's about is neck sizing over full-length sizing for greater brass life, especially in a generous chamber like often found in military rifles - it's not a "Parashooter" discovery. Not to besmirch Parashooter (nor even to disagree with him) - he's a wonderful contributor to many forums.

The other "trick" (shimming rimmed cartridges when headspace is out, then headspacing on the shoulder) is a separate, but related issue.

I shoot 303 Brit and always neck size or partial full-length size. I get 10++ reloads in a P14, and five of so in a Lee Enfield.

 

[aletheuo]

The other "trick" (shimming rimmed cartridges when headspace is out, then headspacing on the shoulder) is a separate, but related issue.
I shoot 303 Brit and always neck size or partial full-length size. I get 10++ reloads in a P14, and five of so in a Lee Enfield.

Since I wrote the question in the first place and gave an appropriate title to the thread - It is not a separate issue. It is THE issue we are discussing! The issue I wished to converse about is the shimming of rimmed cartridges when headspace is out and/or chamber is sloppy - as it relates to the 303 british cartridge. I think the majority of 303 reloaders are necksizers/PFL only and they get the exact same brass life as you in an LE.

The point being here is that you can buy new brass, fireform in the usual manner, necksize only, and STILL slowly observe the webbing get thinner and thinner until you decide you won't take a chance on it anymore - a ticking time bomb so to speak if you want to gamble. You have enough experience to know this is true. I don't know about you but this makes me uncomfortable even if the enfield is designed to handle escaping gas in a decent manner.

Cartridges that are headspaced on the shoulder show none of this webbing stretch and therefore you can get 15-20 reloadings or more and you don't feel like you are even gambling by using the older brass. Parashooter has offered his successful experience with this method and I would like to know if what other's experiences are with it. And yes, I only have one No4 mk1 enfield and so I don't need to track any of the brass with other chambers.

In the interests of safety - before I try this shimming for fireforming method myself - I was wondering what others' experiences were with it. I find that it's not wise to just take one person's experience with some crazy experiment and then roll with it - I would rather know that there is a consensus that this will be safe to do, that is does indeed extend brass life as parashooter has alluded to.

My gut instinct is that if the cartridge was designed to headspace on the rim that it probably should be used that way - but it appears that in practicality it can headspace on the shoulder just fine.

 

[Ganderite]

The problem of stretching cases is not becasue it is rimmed and not shoulder supported. The problem is that the L.E. is a rear locker. On firing the entire bolt is elastic and compresses - stretching the brass. A P14 does not have this problem.

If the headspce is "generous" (and it often is) and if the cases are full length sized each time, the firing pin and the primer drive the case forwards, off the bolt face. Then pressure sticks the case to the chamber wall and pushes the case head back onto the bolt face - stretching the case.

What you want is a case that is a bit long, so the shoulder engages the chamber and pushed the case head firmly against bolt face. The L.E. has a lot of cam action on closing, so the bolt will easily engage the locking lugs and start to turn down. Ideally you wnat to feel resisitance on the last half to third of closing.

Your fired brass is already long, so when you size, neck size or back out the FL die so you don't push the shoulder back.

If you have brand new brass (but don't do this with factory ammo) you can eliminate the initial stratch on first firing by loading with the start load (or loading a cast bullet load) and lubing the cases. The cases will set back onto the bolt face without stretching. After this treatment, be sure to clean all the lube out of the chamber.

 

[aletheuo]

If you have brand new brass (but don't do this with factory ammo) you can eliminate the initial stratch on first firing by loading with the start load (or loading a cast bullet load) and lubing the cases. The cases will set back onto the bolt face without stretching. After this treatment, be sure to clean all the lube out of the chamber.

So what you are saying here is that this is another option to produce chamber length brass to give longer case life. The three options I have seen are then are:

Can use on factory ammo:
a) shim the rim on first firing with o-ring or other spacer material... (as parashooter has demonstrated)

Only use on reduced handloads/cast loads:
b) lube cases on first firing with a reduced or starting load (clean cases and chamber afterwards)
c) seat the bullet long, uncrimped on first firing and use the camming action of the bolt to seat bullet ogive at lands to be sure the case head is right at the boltface (edit - a later post gives another perspective: seat the cast bullet so that it engages the rifling hard with a full crimp. Seating a factory bullet backwards will also engage the rifling hard)

Does this look correct?

 

[44Bore]

I have found that I get better results by using a cast bullet seated well out of the case to hold it back against the bolt head to fireform. I also use this method with jacketed bullets in some rifles. I usually get good results with a load that is just a bit above the starting load.

44Bore

 

[cosmic]

Aleth - All these methods eliminate the large axial case stretching at the web on first firing. I dont bother with this - I just partially resize my cases on subsequent firings, to eliminate any additional large axial stretch cycles. My feeling is that case fatigue is cumulative, and I can get away with one stretch, as long as I mind subsequent firings.
As I shoot several rifles with the same reloads, I resize to a slight interference in the tightest chamber. Accordingly, some rifles would headspace upon the rim, some upon the shoulder. I'm getting more expansion per cycle than brass that is necksized only in one rifle, so I cant expect indefinite life.
I'm not sure that any fireforming method is particularly advantageous - bear in mind that LE chambers are also oversize in dia, which also causes thinning of the case walls.
FWIW - Parashooters method has been developed to accomodate rifles with large headspace. Headspace on LE's is not a "black and white" matter. There have been many thousands of rounds shot out of rifles with out of spec headspace.... So, the selection of a first firing method is somewhat subjective, and (perhaps) the benefits are somewhat subjective.

 

[Tyler]

I'm willing to bet that orthodontic elastics will work well on .303 brass, if you still seek a spacer. Back in the days when I had braces, I recall that they might be just the right size to slip over the casing and stay over the rim.

Food for thought.

 

[PerversPépère]

There's also a way of forming a secondary shoulder to get the cases to the correct length: us a slightly oversize expander (.320) to enlarge the neck then resize the neck partially with the correct expander after that, taking care to leave that secondary step.
You need to find the correct length by trial and correction until your bolt closes just tight.
Then load these cases with a forming load (small pistol powder charge - 8 grains of Red Dot- topped with Cream Of Wheat and a small Parowax stopper).
The brass won't have anyplace to go and will fireform perfectly. Neck size for all other subsequent reloadings.
PP.

 

[bigedp51]

I have used the o-ring method and both Parashooter and I read about it at the old jouster Enfield forum and Parashooter decided to try weed whacker nylon cord/string, the original poster was Canadian and he used rubber o-rings as taught to him by another Canadian. What was remarkable no duct tape was involved (Red Green joke from an American)

The o-ring method works BUT if possible I decrease headspace to the extreme and I have one No.2 with the headspace set at .061/.062 to prevent case stretching in the web area. (my Remington case rim thickness is .058)

Here is the real problem, American made cases and ammunition are downloaded to less than 43,000 CUP due to all the older SMLEs being used, when you load these cases beyond 43,000CUP they fall apart very quickly. The American ammunition manufactures use five different grades of brass to make cases, I think our .303 cases are being made from the same quality or spec as the 30-30 and 30-40 cases are.

I bought 500 once fired Greek HXP cases and was surprised to find NO stretching or thinning in the web area so this has to do with the quality of the brass because it was designed for higher military pressures.

NOTE: below is a photo of a Privi case which is the thickest of any cases measured in the web area.

Below is a Privi case on the left and a Greek HXP case on the right, the privi cases have thicker rims and base diameter of any of the cases I have checked.

Below is a Winchester case fired in my Enfield with the headspace set at .067/.066 and the factory case thinned in the web area. .009 (nine thousandths) without a o-ring
PLEASE NOTE the rim thickness is .058 the headspace is .067. (.067 - .058 = .009 ) the case will stretch as much as you let it, the air gap between the rear of the case and the bolt face is called head gap clearance and the *case will stretch to fill this void.

*American made cases are a little wimpy and do not like excess headspace and fat chambers.

The o-ring trick works BUT it does not help center the case and you can end up with more expansion on one side of the case with the possibility of a warped or banana shaped case that holds the bullet off center in relation to the bore when reloaded

 

[bigedp51]

As a side note the book below recommends setting your headspace .003 over your rim thickness (no o-rings needed)

Below a warped banana shaped American made case fired in an Enfield chamber with more headspace and chamber diameter than it could withstand.

Please note that the primer has backed out of the primer pocket also (long headspace and a fat chamber)

 

[aletheuo]

The o-ring method works BUT if possible I decrease headspace to the extreme and I have one No.2 with the headspace set at .061/.062 to prevent case stretching in the web area. (my Remington case rim thickness is .058)

Have you tried to see how many firings you can get out of one case with the headspace set at .061?
How many firings with the o-ring method?

I bought 500 once fired Greek HXP cases and was surprised to find NO stretching or thinning in the web area

Do you know for sure that the Greek HXP cases were fired from a LE rather than a P14 or something else? Who knows what the head gap clearance was on this rifle. In the pic it looks like the greek case took a bad hit to the webbing, too.

Thank you for your informative post - took you a while to make it I'm sure. Thanks for going to all the trouble.

 

[Ganderite]

Aletheuo "c) seat the bullet long, uncrimped on first firing and use the camming action of the bolt to seat bullet ogive at lands to be sure the case head is right at the boltface"

Not quite. I seat the cast bullet so that it engages the rifling hard with a full crimp. I don't want the primer pressure to shove the case forward, off the bolt. In that the primer delivers a lot of pressure, I suspect the bullet and case still get shoved forward a bit, but not as much as usual. I have also used jacketed bullets loaded upside down. They really have a resitance to the rifling.

I prefer to use the lubed case method with cast bullet loads. Simple and cheap, and good practice from the standing position at 25 yards.

 

[aletheuo]

Not quite. I seat the cast bullet so that it engages the rifling hard with a full crimp... I have also used jacketed bullets loaded upside down. They really have a resitance to the rifling.

k - edited my post accordingly. Thx

 

[bigedp51]

Aletheuo

The 500 Greek HXP cases I purchased from Brian #### at http://www.bdlltd.com/ , these cases were fired in several different type machine guns and several different rifles, what is notable is NONE of these cases had any thinning in the web area what so ever. The HXP brass seems to be softer or more flexible because it would bend BUT the HXP cases varied greatly in weight and uniformity.

On the No.4 Mk2 I have only been able to fire my Remington cases three times but the cases have only thinned .0005 (half a thousandths) after three reloadings.

I did not buy into the rear locking lugs and flexing action blame game for short case life and reloading, I received an email from a person in the UK who had reloaded his HXP cases over 30 times with no ill affects, so I started checking my American made cases and came to the conclusion that 90% of our problems was these derated cases and pressure.

Below a Winchester case that was reloaded three times at near max pressure and failed please notice that the crack in the case is at an angle and not uniform, this case expanded on one side more than the other and became banana shaped with the base of the case no longer 90 degrees to the axis of the bore

In the example below it shows the undersize case in the oversize chamber and why the case expands on one side and not the other, the case is “speared or pinned” in place by the firing pin and can not move. What you end up with is a case the has the bullet out of alignment with the bore every time it is reloaded.

By decreasing the headspace you are shoving the case further into the chamber and reducing alignment error.

Below SAAMI case and chamber dimensions

As a side note a champion Canadian shooter visited us at our old Jouster website and stated he was so dissatisfied with the construction/quality of current .303 brass he converted his .303 to use .308 cases while retaining the .303 bore for reloading or a .303/.308 wildcat to get better case life from his Enfields.

 

[aletheuo]

As a side note a champion Canadian shooter visited us at our old Jouster website and stated he was so dissatisfied with the construction/quality of current .303 brass he converted his .303 to use .308 cases while retaining the .303 bore for reloading or a .303/.308 wildcat to get better case life from his Enfields.

When I saw parashooter's mod of the 303 case to rimless and how well it stood up I immediately thought to myself "what rimless 30 caliber case could you safely fireform in the standard 303 chamber?" I'd prefer someone else perform this experiment - at a distance - string to trigger - in a lead sled. ;o)