Muzzleloading shotgun questions

[DocHunter]

I have a caplock doublebarrel muzzleloading shotgun with Damascus twists barrels that I want to try to use for turkey hunting this spring. According to information in the Dixie Gun Works catalog, this gun should be safe with up to about 82 grains of FFg black powder. I would like to use size 4, 5, or 6 shot and would like some advice about how to maximize the density of the shot pattern and the best loads to try for such a gun. Both barrels measure 0.714 inch. at the muzzle, which, I think, corresponds to cylinder bore. I would also like to use Shockey Gold black powder substitute from American Pioneer Powder instead of black powder for the benefit of less fouling and easier cleanup. This product is supposed to be able to be substituted in equal volumes for black powder, and I think develops less pressure than an equal volume of black powder and would therefore be a safe substitute if I am correct. I want to try some loads and pattern this gun as soon as the weather here permits, so any advice on loads would be appreciated.[