Case separation in a .303

leadslinger said:
I either have a sloppy chamber or a head space issue.
I am thinking bad chamber.
I will look into getting Lee collet dies, as i want to keep using it at the Milsurps.
With the right load, i can get some really nice groups at 100 yards as well.
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I've been reloading .303 Br for 2 years now. I also use light Speer 150 gr bullets. I have achieved remarkable accuracy in my No4 MK2, but the cases only lasted for 4-5 reloads and then the heads separated.

I did 3 things, I replaced the bolt head 1 with a no 2 and I applied a very light oil coat to my cartridges the night before I went to the range. This helps in some way during the firing process and prevents the case heads from separating. The third thing I did was to use the heaviest (thickest) cases available. They achieve the required velocity (2600 fps) with less powder and lasts longer. I switched from Winchester (thin) to PMP (thick)cases.

Because of the rifles design, the .303 Enfield will allways be heavier on cases than rifles with forward locking lugs, but with these 3 simple steps I have stretched some cases to 10 reloads before the seperation occurs.

My chamber is so big that the fired 303 cases looks more like a 303 epps case with a rounded Weatherby shoulder.

Always use new cases when hunting. You dont want a case seperation in the hunting field!
 
Don't, under any circumstances oil bullet cases prior to firing! The bolt takes the worst of the pressure when firing, but a dry case gripping a dry chamber prevents the bolt from receiving all of the pressure! Don't even let your ammunition get wet when shooting in the rain as a wet case is also unable to grip the chamber wall.

I would advise against neck sizing for the Enfield as the case can stretch beyond the limit of the chamber due to the bolt buckling during firing. If you have ever seen a slow motion replay of an Enfield firing, you will know what I mean!

Lastly, I prefer to use IVI military ammunition and just add my own powder and bullet (Mexican Match!)
 
shooter64 said:
Don't, under any circumstances oil bullet cases prior to firing! The bolt takes the worst of the pressure when firing, but a dry case gripping a dry chamber prevents the bolt from receiving all of the pressure! Don't even let your ammunition get wet when shooting in the rain as a wet case is also unable to grip the chamber wall.
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What a wonderful attribute for a military rifle to have in the mud and muck of the battlefield......:rolleyes:
 
i have it happen with my smle but seems to only happen with sellier and bellot cases.. just keep ur loads light and ull be fine
 
Old SMLE's and wartime No.4's are the worst for having sloppy chambers. One thing you can do to preserve your brass is make sure both lugs are bearing. If only one lug touches, the whole action torques to one side on firing. The fired case is actually visibly bent, with a bright ring on the head. SMLE's are the most flexible, but the No.4 flexes quite a bit, too. Just look at the rear of the locking lugs, and make sure that there are bright spots on both, indicating proper bearing. If not, correct the situation by stoning the lug that IS touching, then adjust headspace.
 
I'm not a 303 Brit case separation denier, but I've shot 100's of rounds from several different guns and never had one, not even signs of one (in the first five firings anyways - I haven't gone past five yet).
 
Lee Enfield #4's are hard on brass for reloading. If you full length resize you will be lucky to get 3-4 reloads on the brass because of the internal web design of the cartridge case. P-14's are no where near as hard on brass. Never head to the range with reloaded .303 unless you have a broken case extractor from Brownell's. My worst experience was 2 case separations during a timed WW2 re-enactor match using 1944 dated brass.
 
one day this last summer i shot 50 rds. out of my jungle carbine. i had 5 case head seperations. that is the price you pay for using the same brass in three different smelly's. i used my ruptured case extractor to pull the cases out, and kept on shooting. i used to see ruptured case extractor's at the gunshows for $3 but i have not seen one at a gunshow for quite a while. if you own a smelly, and you reload for it, you absolutley need one.
 
When a case separates in this manner, the foreward portion is usually not tight in the chamber. Running another round into it, or using a brush will generally pull it out. Sometimes it will fall out, if the rifle is pointed up. A broken case remover is handy.
If you are using pickup range brass in .303, always inspect it very carefully. You will usually find cases with incipeint separations, resulting from the first firing. With ex-Ranger brass (i.e. gov't issue rifles), the cull rate can go to 20%. The Lee Enfield design doesn't help, and there are some very loose rifles out there.
 
I haven't read all the posts, but here is the way it works.
Excessive head space, and not excessive pressure, causes the breaks a bit forward of the rim. Firing any factory load will cause this, though some brands of brass may stand it better than others. Same applies to a sized reload.
Here is what happens when the round fires. The firing pin drives the case forward, then it fires. Friction on the case wall holds the case forward, as the pressure drives the base of the case back to the bolt face, thus stretching the case.
If you want to reload for your rifle with the excessive head space and have the brass last, here is what you have to do. You must get new brass. In leu of that, you could pull the bullets from loaded rounds and dump out the powder.
Load a light load of a fast powder, such as Unique. CAst bullets are ideal for this operation. Seat the bullet so far out that it makes hard contact with the rifling and the bolt is hard to close. Fire the round.
The case is now fire formed to fit your rifle and the cartridge is now head spaced on the shoulder, instead of the rim, where it was designed to be head spaced.
Do not size the case from here on in, in any manor that will push the shoulder back. Your brass should now last a normal amount of loadings, with normal, factory pressure loads.
 
In addition to H4831's excellent (as always) advice above, using o-rings or tape as described in this thread:

http://www.canadiangunnutz.com/forum/showthread.php?t=423379

may help prolong case life as well. In theory it should help prevent stetching one side of the case more than the other and prevent 'Crooked Casehead Syndrome' and only needs to be done once. I haven't tried this but I plan to and it makes sense to me.

Even if you don't go to the trouble to fireform with a light load as described above, neck sizing or partial full length resizing from now on will help a lot.

Just set up your full length die such that it touches the shell holder at full stroke, then back it off a full turn. You will now be partially full length resizing. You'll be able to see on the neck how far down it has been sized.

After a few loadings, if the brass becomes difficult to chamber, screw the sizing die down further until you find the point at which the case will chamber easily again and resize them all that way for one reload, then go back to partial sizing.

With medium to mild loads your brass can be made to last quite well this way.

If you have more than one .303 rifle you must keep separate brass for each.
 
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After much reading on the subject, the headspace is not the issue. The problem is the "generous" chamber dimensions of the Enfield. The reloading dies also size the brass down so they will fit in any Enfield, this makes the brass smaller than it needs to be and cold works the brass and causing early failure. Neck sizing and moderate loading helps, but eventually the brass will fail.
 
H4831 has it down pat, I couldn't have said it better myself.
I will add that a neck size die should be used because the FLS die
will resize the shoulders if you try to do it on the cheap, a Lee collet
die is also a very good alternative if not an overall better die to begin with.
You will need three dies no matter how you cut it, this holds true for any caliber but especially with the Lee Enfields due to their rear locking lugs and loose chambers, of coarse this all adds to their great reliability but doesn't help when it comes to handloading.
bigbull
 
bigbull said:
...I will add that a neck size die should be used because the FLS die
will resize the shoulders if you try to do it on the cheap...
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In my experience the shoulder of the .303 case is not touched at all when partially sizing with a full length die.

The lower part of the case, yes. The shoulder, no.

There is no need to buy more dies to get this done.
 
TwoTone said:
In my experience the shoulder of the .303 case is not touched at all when partially sizing with a full length die.

The lower part of the case, yes. The shoulder, no.

There is no need to buy more dies to get this done.
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No, Bigbull was right and it was something I just neglected to say.
By using the full length sizing die for neck sizing, the die squeezes down the diameter of the case, near the shoulder, before the die actually toches the shoulder itself.
 
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