Proving is a process. The hoped for end of the proving process is a proof (reasoned argument to the end of expressing the probability that something may be expected to function tomorrow as it does today) Ask any geometer. The provers in this case aren't academicians so they're allowed to consider themselves proofers, or proofmasters, or prooflackeys, or proofies. I believe guns are proved in a certain condition and the proof is valid so long as the gun (barrel) remains in that condition.

jack