For my stoeger P350 Winchester buck shot seems to be the best. I have rounds everywhere and none in the box I wish I could tell you exactly what type but i don't know it's old.
But i shoot buck with a full choke and it patterns well enough to nail a man at 30 yards or so.
Best thing I could suggest is try some other chokes with some different loads and see what your gun likes.
"come on you sons of b***hs! do you want to live forever?" Sergeant Daniel Daly, USMC, Belleau Wood France June 6th 1918
"You can be as mad as a mad dog at the way things went. You could swear, curse the fates, but when it comes to the end, you have to let go" Benjamin Button