Thank you for your response.

Far from being awed and mystified by the proof house,I had occasion recently to prove 2 guns and I posted on another thread exactly what happened in an attempt to clarify this rather obscure process. In short there was nothing done that could not be performed by a decent gunsmith with proper safety precautions.
Indeed our proof act does not even require somebody who works on their own gun to prove it at all. I is just a legal requirment when it is to be offered for sale/transfer.

Modern mass produced guns proberbly do not need it. There is an enormous safety margin built in and I am sure that the US manufacturere do some form of proving themselves in the form of test firing.

I did see guns that had failed proof testing, many. They were on the shelves of the proof house and in the pictures on their walls.
Each one of those was a life or hand saved.
I post on other forums, I have seen pictures posted there, of guns that have failed dramatically often following conversions to larger calibers than the originals or other unwise modification. Constantly there are posts from people proposing modifications that are unwise and unsafe. i.e. just a few days ago a small ring large thread Kar 98 to a 7mm magnum when the action is only by best recommended pratice, good for 37,000 CUP.
Our proof system is not perfect, but it should stop shoddy or dangerous work being sold to an unsuspecting shooter.
It does stop "Bubba'd" guns unless only "Bubba" is ever going to fire them.

Another factor to consider in this word of litigation is that my conversion for instence can be sold. I am on solid legal ground. It has been proved to be fit for purpose, just the same as a H+H, Purdy et al. There was a thread on this forum a few months ago about the dangers of selling any modified gun in the states because of future litigation as its safety could not be legaly demonstrated.

Regards