What grouseman said on the Breakfree. Since I started using it a few years ago I can't recall a jam on three different 1100s and a 1187. I put it on pretty heavy. Don't know if it's the best but it's the best I've used in over 30 years of shooting semi-auto shotguns.

One other thing is to make sure the chamber is free of plastic shotshell build up. I hit that heavy with a Tornado brush or bore brush wrapped in 0000 steel wool.