303 British advise needed....

[Dantforth]

I have a new (to me) No.4 Mk.1 which has seen a few miles. I shot some military ball in it today (Dominion 1945) and have some concerns regarding the fired brass. Headspace was O.K. Brass is really swollen.....458" just above base, .436" half way up the body, .409" body just below neck, .344"...neck. It seems to be worse than brass from other rifles I have but can't compare as I have it all loaded. I do have a Lee collet die so will neck size. Can any of you experts comment about the dimensions of the fired case?

 

[tiriaq]

According to Donnelly (The Handloader's Manual of Cartridge Conversions) the diameter at the head is .456", and at the soulder .412". It may be that your brass is a little on the small side, unfired, so it looks expanded at the ring. According to these numbers, you're in the acceptable range.
I believe the maximum diameter for a SMLE chamber mouth is .464".

 

[Dantforth]

Whew!!! That makes me feel better. I need some new reloading manuals which are up to date. Thanks...Dave