[Crankylove]

3.8 grains of W231 or HP-38 with a 125 grain bullet makes for a very accurate load, with very little recoil in my 4"GP-100.

My favorite plinking load is 3.8 grains of the W231/HP-38 with a 158 grain cast SWC.........it gives blistering speeds of about 650-700 fps.

As far as the crimp, I do just enough to remove the flare from the case mouth after seating. Lightweight guns with heavy loads may require a heavy crimp to prevent the bullets from walking out of the case under recoil, but that has never been a problem with my GP-100.