Here are some pics of the shooting. I don't know how to post them in order but they are marked and here is the information:
ball photo, shot with 2 drams or 55 grains just to see the rifling on the equator and take measurements,
4 and 6 drams (110 and 165 grains) print apart
8 drams (220 grains) is apart but closer
10 drams (275 grains) is even better
12 drams (330 grains is just right) 14 drams or 385 grains printed the same but I lost the target!
16 drams (440 grains) is too fast and cross fired.
Power was FFg GOEX, 209 primer, brass case 3 3/4 long, spherical ball of 1400 grains which is actually a 5-bore.