Well it is noted that both of the Parkers which Bell finally blew up took approx 30K psi to do the trick. Both of those guns would have passed proof. Buck Hamlin on one occasion took a hammer L C Smith 12ga Damascus & "Re-Chambered it for the 3" shell. He then proceded to start with the max load of Blue Dot from Alliants manual & worked "UP". I don't recall that he actually had pressure testing equipment, but he loaded considerably higher than the max, in fact as I recall all he could get in the hull. That gun would undoubtably have passed even the 3" proof.
Bottom line is we have learned to live with the system which has been in place since the first breech loader was fired on these shores. To try to go back & make anything retroactive & start re-proofing century old guns now is just not in anyones best interest.
I don't personally recommend it, but I know a good number of 20ga guns have been re-chambered for the 3" shell & used on a regular basis with the magnum loads. The whole idea here was to protect the "Masses". If I still had an FFL I would probably be all for this. I could then buy up old guns, rechamber them, let them pass proof & make a good return on my investment, selling them to the "Masses". I really wouldn't do this though as I try to discourage the use of modern loads in old guns.
I'm not submitting mine as a guinea pig, remember I'm talking "AGAINST" proof, not for it. But don't kid yourself, the major portion of those guns you are calling dangerous will pass the proof. Then they would have oficial sanction to cram any load one wants in them.
Yes I believe some 3" 20s have been loaded up to 1300fps, but some 12s have been loaded up to 1400fps or beyond. Generally speaking for the same charge of shot a 20 will have less muzzle velocity than a 12, BUT, YOU Know That Don't You??
