If by "conventional" you mean "American factory loads", as in from Win/Rem/Fed . . . I'd guess you wouldn't have a problem with a Fulton, although if it's early enough (you can tell when it was made by serial number), it likely has factory short (2 5/8") chambers and was built to use shells that produce somewhat lower pressure--about 1,000 psi--than current factory loads. I would not worry about modern target loads, 1 1/8 oz or less at moderate velocities, but I'd likely stay away from loads with heavier shot charges or extremely high velocities.
