Those post-war Webley & Scott guns have also been something of a quandary for me. By their markings--and the tons are service pressure rather than proof pressure, as Drew indicated--they fall a little short of SAAMI service pressure standards even when bumped up from LUP to psi, yet were made for export to the USA. Across the board, they're pretty light guns. I wouldn't hesitate to shoot standard American target loads in them, preferably with velocities on the modest side, but I wouldn't want to shoot the Winchester 1 oz 28's in a 728, nor a 1500 fps 1 1/4 oz field load in a Model 700 12ga. I owned a very nice 720--basically a 702 20ga made for the American market. 3" chambers. That gun weighed right around 5 3/4. One ounce loads were none too comfortable. I can't imagine magnums. But I guess the Brits realized we Yanks had a case of magnumitis back then, and were especially enamored of the 3" 20.
