[StubTwist]

Paul, are you sure 4 drams? I checked Goex's site for the 3" 12ga. load with 1 1/2oz of shot. 1 dram equals 27.3 grains of black powder. 102 grains / 27.3 = 3.73 drams. A pretty stout load! Your idea to start with 3 1/2 drams is a good start