I purchased a P14 Remingtom 303 at auction and today at the first range test, the shells were fireforming to something else. Seems it's been recut to 303 Epps Improved. Quite a bit of extra powder capacity to the improved case.

Nothing wrong with that, you did well.

I like it.
I'd be interested to see what it does with some good hand loads over a chronograph.

Man, you've got a neat project that can last a good long while. The barrel wasn't remarked or anything??

Thats looks like a Epps to me too B A W. you're in for an adventure now!

I'll bet it feeds smoother than goose poop too!

Back in the late 60s/early 70s when Elwood was still alive and working hard very day I had him do several P-14s in chamberings such as .22 Epps Improved Zipper for me and they all fed perfectly when delivered from him.

That looks cool and a rifle similar to what I've been dreaming of building. I've been wanting to find the right action for a .30-40 Improved. It was one of PO Ackley's best cartridges to improve, I'll bet your .303 is very similar.

Examination of the fired cases showed some primers were backing out of the pocket and the case not fireforming correctly. Consulting with a friend today, he suggested expanding the necks to .338 and then resizing down just to the Epps shoulder to give the case more support during fireforming.

I realise 303 Brit headspaces on the rim but this step makes good sense to me. The bolt just firmly closes on a loaded round by this proceedure.

As you know, a magnum head spaces on the belt but to get the best performance and longest case life, folks reload them to head space on the shoulders. I suspect that will be the case in your case.

First attempt at forming cases, neck expanded to .338 then resized to just fit the chamber ready for fireforming.

not for nothing.. no reason to form the ghost shoulder on a rimmed round.. headspace is on the rim.. right?

I have been running 2 303 epps for a while now 1 on a #4 action the other on a P14 never had a problem with fireforming brass in either of them.

Forgot to add in last post Steve Redgwell (think thats it) has written some interesting stuff about and lists loads for the 303 epps amongst other interesting Epps chambereings i beleive you can see some at www.303british.com