7 drams was my heavy load for my double 12 bore with round ball - 1,550fps. Also the heavy 12 bore load listed in WW Greener's 9th edition.

My pelter only weighed 7 1./2 pounds and too many of those broke cracked the wrist stock. Stock repaired & all OK - and the present owner is using it to kill his moose, dear and black bear along with grouse, annually.