I've only shot my 7/8-ounce, 1200 fps, 6300 psi, Remington STS reloads in my 310AS 12-gauge. Wouldn't hesitate to use stouter loads if I took it hunting where I felt that necessary. Once upon a time I took my 1947 vintage 16-gauge Model 310ASE when I went Pheasant hunting with a bunch of yahoos. After they had expended their loads I thought to myself "what the hell" and dropped into the back trigger for the left .030" choke barrel where I had a Remington Express #5, gave cock John a long lead and damn if he didn't fold up. Probably blind luck, but an honest 55-yard shot. I'm sure the great bulk of the Pheasants I've shot in 63 years were under 35 yards.
I need to find a couple of boxes of Gyttorp shotgun shells to display with my Husqvarnas.