You can’t buy black powder or percussion caps in NY? Seriously?
There goes my plan to arm myself with a LeMat revolver in the absurdly unlikely event that I move to New York...!
yes you can.
but if you own a cap and ball revolver, you cannot keep the powder, ball/shot and cap in the same residence that you have the gun....
....well you can have some of the items as long as one of the necessary item, needed to fire it, is missing.
Your LeMat of course is a shotgun with a revolver wrapped around it...and neither you, nor General Beauregard could fire one in NY State without special dispensation from Pope Andrew the first...