I shoot .684" or .710" (whatever's handy) round balls in my Mossy (3 1/2" chamber) with a plastic cup-wad underneath the ball using 2 3/4" hulls and a descent load of Herco. The velocity is 1,600fps and it punches single holes, about 1 3/4" to 2" in diameter for 5 shots at 30 yards. I could increase the velocity, ie: power, with longer hulls, but the load I'm using duplicates or slightly betters the African 7 dram 12 gauge load listed by W.W.Greener. It's enough for me, here in Canada & is easy to shoot with very reasonable pressure, under 11,000psi - apparently.