I have an H&R ultra slug .....use the lightfield exp's , 3" groups at 100 and 5" at 150. Thats great for a shotgun. Tried almost all the brands of slugs ....IMO , winchester/remington werent very good. Got the best results from federal & lightfield. Tried 3" as well as 2 3/4 .....3's dropped fast past 100ys. Make sure you get a scope with plenty of eye relief.