I've had great luck with Brenneke 2 3/4" and 3" KO Sabots (not the other KO slug). They shoot a 63 caliber one ounce slug at 1600 fps. They hammer deer and are very accurate in my Marlin 512.This year I'm shooting Hornady 300 gr sabots, and they are knocking the bullseye out at 100 yds, so I have no doubt they will work just fine on deer.

With slug guns, you just have to find something the gun will shoot accurately. I start with the stuff on the lower end of the price scale and only switch brands if they don't shoot well enough. I don't shoot much past 100 yds, so I don't bother with the stuff around 2000 fps. I tried Hornady H2K once, and my gun sprayed them all over the place.