303 British Epps Improved

[davide montini]

The grand son of Elwood Epps has a shop in Ontario called wise choice something.....when time permits for me ...this young man will be making me one ...I spoke to him and is a well spoken person...nice guy as well
Ya life gets in the way !!

 

[WhelanLad]

jealous ! wish my ruger 1 chamber was accidently a epps lol

 

[Potashminer]

... Suggested a barrel switch but the threads will probably not match....

Have no doubt about that - the barrel tenon threads are not the same - they had different diameters - LE were 14 TPI "V" shape 55 degree, whereas P14 was 10 TPI Square threads. Not a chance of unscrewing from one and screwing into the other. Might be possible to turn down the barrel tenon on a lathe, install a sleeve, then, thread that sleeve for the new receiver - no clue if that would work or be strong enough, but way beyond a simple "unscrew" from one and "screw into" the other... Would be a very fussy thing to do and, at same time, to hit correct headspace and extractor slot timing. Still end up not knowing if that "Epps" chamber is really a match to the "Epps" dies, without casting the chamber and doing good measurements.

 

[diegocn]

This thread answered a long time mystery of mine. I've seen someone elses 303 case came out exactly like yours!

It was a father and daughter doing their supervised shoot at the local indoor range. First shot we thought something was off with the fired brass, 2nd shot had a case head separation in the rifle and lots of smoke. The store clerk tried to talk him out of firing more but he proceeded to load the 3rd into the chamber. That's when I stood up and ran away.

I thought his headspacing was really off, the store clerk thought he had a 410 enfield musket. But now I know it's probably one of the 303 wildcats.

 

[bigedp51]

A British .303 Enfield rifle at the max military headspace of .074 and a rim thickness of .058 will have .016 head clearance.

The head clearance is the amount of "Air Space" between the bolt face and the rear of the case.

And with most bolt action rifles you want to only bump the case shoulder back .001 to .002, and this would be the approximate head clearance.

The reason you have case head separations is because the case stretches and thins when fired. And the more head clearance you have the more the case can stretch.

I have had Winchester .303 British cases start to seperate on their 2nd reloading. And this was because I was full length resizing the cases and not letting the case headspace on the case shoulder. In my testing the Winchester cases were the worst and Prvi Partizan cases were the best for reloading and case life.

Below these .308 cases were fired in a brand new Savage rifle and the resizing die was setup per the instructions. Meaning the die was makeing hard contact with the shell holder with press cam over. The article made no mention of the amount of shoulder bump, but it does shows the quality of the brass and case construction in relation to case life.

Below on the left is a .303 British case that was fired with reduced cast loads. The case did not stretch at reduced chamber pressures and only the primer backed out. And at low pressures, the primer will back out by the amount of head clearance your rifle has.

My 30-30 Winchester 94 at the max chamber pressure of 42,000 psi always has the primers protruding. But my Enfield rifles at the max chamber pressure of 49,000 psi will cause the case to stretch to the rear to contact the bolt face. So if you are going to load the .303 British on the hot side you need to neck size only or full length resize with the minimum amount of shoulder bump.

Bottom line, you can't make a .303 Epps Improved into a .308 Winchester. And the .308 Winchester rifles and cases were designed for higher pressures.

And from looking at the OPs photos I would say he has a standard .303 British military chamber.

 

[John Y Cannuck]

IMO, the Op has a standard British rather crude chamber, made to fire rough dirty cartridges in the trenches of WW1. The ammo of the period was rather loose in spec as well. A fact that along with the mud, raised big problems with the much better chambered Ross rifles.

Resizing the case will quickly result in head separations, unless you neck size only, and even then case life will be short.

Not sure if they still offer the service but RCBS used to make custom dies. IIRC it involved sending them three fired cases, and a chunk of your wallet. I can't say how much of an improvement the added expense would make to case life over simple neck sizing, it's simply an option. I expect not a hell of a lot of improvement.

All my 303's have smaller versions of the blown forward rounded case you show, except my Ross. It still retains it's original unmodified chamber.

 

[kawicrash]

I had a '42 Maltby that I jokingly called a .303 improved because the fired shoulder moved so far forward and rounded just like the OP's pic.

 

[bdft]

I had a 1905 Ross that was the same. Field expedient chamber modification probably. Cases didn't last long in that one.