If you missed the enlightening conversation between Beerhunter and Captain Laidler today about proof marks, here's their conversation:

Seaspriter: Was the Birmingham Proof House a separate, independent entity from Birmingham Small Arms (BSA)?

Beerhunter: Yes. Absolutely. http://www.gunproof.com/ And there is an older Proof House in London Worshipful Company of Gunmakers Between them they have a Statutory responsibility for gun Proof in the UKicon .

Peter Laidlericon: Proof houses..... They really are nothing more than self perpetuating quasi autonomous non government organisations - or QUANGO's for short. who answer to............., well, nobody really knows! Let me put it like this.......... The way the quaint old 1860 rules were written and re-written since, when the UK Military buy weapons from abroad - and we ain't talking third world here but the likes of the USAicon and Canadaicon ..... and I mean well tried and tested weapons, like M-16's, Miniguns and L116's plus pressure bearing spares then regardless of the proofing or strict manufacturing processes/regime in the manufacturing Country, they have to be re-proofed in the UK at great cost. I mean, what does that say.......

And guess what - again......... The quaint 1860 rules mean that even a blow-back unlocked open bolt fired SMG barrel has to be proofed! Whatever for........? Even in service, even if it were made of the mildest of one-way trip mild steel, It CANNOT fail because the bloody breech block is blowing back!

Ain't answered your Q SS but you can see where I'm coming from

Beerhunter: Couldn't agree more Peter.

There was time when they served a purpose but their testing methods are now archaic and in recent years they have started to get above themselves - making it up as they go along.

We have an opportunity to sort them out soon when the Law Commission looks at Firearms law.

BTW, there is no requirement in law for the Government to have firearms Proofed - they are exempt.