Bramble:
Without looking it up, I'm sure the Directory is correct. There are vastly different factors involved with proving centrefire rifles and shotguns, which 470Rigby has conveniently failed to acknowledge.

470Rigby was a consummate red-herring tosser (or perhaps, just a tosser!) and no longer posts here.

I'm quite biased of course, having taken him to task on a few issues in the past.....

BTW, if you will forgive me the intrusion Bramble, I just re-read this thread and it is clear I mis-understood 4seventy's original post concerning the 32,000 psi figure quoted on page 19 of Ellis Brown's book. He indeed states that in East Germany, after 1950, shotguns were proved at 32,000+ psi, and refers to the Standard Directory of Proof Marks as his source of information.

My copy of the Directory is a little unclear, but in no way supports Ellis Brown's statement! Rather, it refers to a 'standard proof' (for 650 bar operating pressure) where the chamber-pressure must reach 12,329 psi measured by copper crusher. Apparently the proving cartridges must average 13,085 psi for 10 shots, and 14,507 psi for 10 shots if 3" or more long. A 're-enforced proof' was also available in East Germany (presumably for 850 bar guns) which had to record 17,405 psi chamber pressure during proof-firing.

So 4seventy' I would agree entirely with your observation, and join you in asking where Ellis Brown found the 32,000 psi figure?

My 'SD of PM' is undated, but is the Jolex publication distributed by Blacksmith Corporation, if that means anything. The East German data is on page 92.