When I bought my 20ga slug gun fellow recommended Remington buck hammers 2 3/4 inch. They worked great on the paper targets as did the Federal power shocks. I stuck with the buck hammers they have accounted for 4 deer in 4 years destroying the lungs in every one turning them to jello. Never went over 10' from where hit.
Heard they were going to stop making buck hammers and went out and bought every box I could find so I would have enough as long as I live.
But to shoot the slug gun more I started reloading, Use bought components. these thors do well out of my 20ga. never had a paper target get away.

Al