I am nearing completion of a 4-bore muzzle loader. 1.015" bore, 32" barrel, back action lock, 19 pounds.

Dixie Gun Works lists 3 1/2oz shot and 273 grains of powder as the service load. Seems reasonable to me. I figure on working up starting with 100 grains or so. I will of course proof fire it with a hefty charge before I fire it from the shoulder. I am planning on making a 1.000" ball mould. Hopefully shoot a hog with it.

Anyone have any info that might be of help. Ever shot one of these beasts yourself?

Look in African Hunter. Recently there was a very informative article on the same cannon.
Good luck