A couple of “ifs, and buts” here.
Under the 1954 rules, that gun would have been proofed at about 14,000psi. 9682psi is the maximum service pressure you are looking at. Yes, many are the US loads that exceed that, and, sometimes they are light, promotional loads, that are loaded with cheap, fast burning powder and lower quality components. Or not. You really don’t know and, ed is, per usual, spouting BS. Exactly what the pressure of any given US load is, are unpublished, save that it is below, or, equal to SAAMI max.
SAAMI max is too hot for this gun. End of story.
You can either load your own, following a specific low pressure recipe. You can buy low pressure loads produced, here. You can buy CIP spec cartridges, produced either here, or, in Europe. That’s it. There is no other way to insure what pressure the load you feed the guns is.
In my accumulation of stuff (no proper collector, am I) is a 1964 vintage 2 3/4” Beretta Silver Snipe. The very great majority of Snipes have been proofed with superior Italian proof, the same level is applied to 2 3/4” and 3” guns, but, for reasons unbeknownst to me, this one got standard proof, and is so marked. SAAMI max is probably a bit too hot for this gun. But, it is built out of the good stuff, modern, Italian, chrome molybdenum steel, it is a modern design, with plenty of wall thickness, where it counts, and, over the years it has seen a few hot Federal “Pheasants Forever” loads. The gun remains tight, and, I doubt I have enough time or pheasants left to cause this gun serious problems. It is valuable to me only because it was my Dad’s, but, a Snipe 12 gauge is worth around $500.
Doing that with an English gun might not be prudent, for numerous reasons.
Best,
Ted
