I certainly hope this is not the case, since my Krieghoff Ulm Primus Bockbüchsflinte is chambered for the even more powerful 7X75R vom Hofe Super Express (4150 bar vs. 3800 bar for the 7X65R).

The number of manufacturers who offer "break open guns" in caliber 7X65R is legion. Seriously, how much sense would it make for respected and responsible manufacturers to offer a cartridge which threatened to jeopradize the safety of their own products?