With my 870 28" bbl (smoothbore), I couldn't hit the broad side of a barn at 25 yards with rifled slugs, using the standard Rem chokes. Okay, I could hit a target at 25 yards but about 8 inches high and 5 inches to the left. TERRIBLE. I recently got the Wad Wizard choke and now I can sling rifled slugs 100 yards within 3 inches of bullseye. Go figure!

I also I have a Marlin 512 bolt action slug gun. It has a 3" chamber but I've only fired 2 3/4" sabots out of it. It's sighted in for 100 yards and can do 1.5" groups at this range with the Remington Premier Accutip sabots. They are the ONLY slugs I was able to get to group accurately out of that gun. With that said, I haven't tried everything out there. I am able to group about 4" at 200 yards with this gun. I aim about 3-4" high to hit bullseye.