ARP,
Just about any European double will will go off the face if you shoot it enough, thats why they are sent back and fixed every few years...The steels of yesteryear allowed that to happen, its not a big deal, but its a fact....Most of them are off the face and the owners are not aware of it. Also a double can go off the face with one shot if the load is a tad hot for whatever reason...The newer rifles of today like the Searcy, Krieghoff,Merkle, etc. are not as prone to shoot off the face...The only ones that I know of that have shot off the face are the Merkles in 416 Rigby and 375 H&H, and that doesn't surprise me, those rounds are too intense for a double rifle action IMO...