The shorter shells may group better in your gun, but that doesn't mean they will in his. You never know until you try them. You might want to try some of the ones that keep the wad in the bullet as they fly. Like remington buckhammers, or some of the brenneke slugs. Sopposedly they are more stable in flight. Sort of like the fletchings on an arrow.

However my H&R with rifled barrel shoots plain jane winchester rifled slugs pretty darn well, where it shoots the gold magnum brenneke shells with wad still attached merely ok.

Winchester, brenneke/rotwieler, remington, and lightfields are all worth a try. Oh, I forgot federal, they have a new one called the trueball I think that might work well too.

If you talking about shooting these out of a rifled barrel keep in mind it will foul the barrel out pretty quick and you will need to clean it or the accuracy will fall off quickly.

Paul