mini grease groove bullets

[derskeeter]

72 grains of Swiss 1 1/2 grains gives me 1310 fps over my chronograph. When I try to go higher the groups open dramatically. I think I am overdriving the bullet. When I built the rifle I thought that I could use the lighter bullet to learn this blackpowder thing without getting beat up from the recoil. I have since learned that this isn't how this works, and even the heavy bullets don't bother me with the recoil.