My experience as well. My slow ( around 1180) 7/8 12-gauge reloads perform well enough through M. Faster than 1300 seem to like IM or F.My experience w/ 7'8th at 1350 is IM choke is required to make them into a useful pattern. YMMV
I generally shoot M/IM for everything so should be good. I ordered a couple of flats to play with. More curious than anything else since I’ve never shot any 7/8oz shells.My experience w/ 7'8th at 1350 is IM choke is required to make them into a useful pattern. YMMV