Brian,
I hate to disagree with you but I think we need to be very cautious about this. We don’t want any bad reports…..I’m not saying that nitro based powders can’t be used in a gun, I’m saying I think it’s a misapplication to use it in a muzzleloader.
There are too many variables with a muzzleloader to contend with. Patch thickness, ball size, seating pressure, and barrel cleanliness will vary from shot to shot. And they’ll all affect chamber pressure. As I said earlier a 5% over charge when reloading modern smokeless powder cartridges is a big deal. I’d stick to Black Powder because you know you can’t blow the gun up that way.
Rootski
(Still alive after years of shooting a .50 cal Hawken, a 12ga double barrel, and an 1860 Colt Army.)