Well, for one thing BHB, you really need to find out the rate of twist in your barrel to figure out what bullet is likely to shoot best.

It's easy to do. Clean the barrel well, then put a very tight patch on the ramrod so that the rod rotates with the rifling as you push it down the barrel. Push the patched rod down the bore and then put a piece of masking tape/painters tape/etc. aroundthe rod right right at the muzzle. With a pen/pencil/marker put a dot on the tape so that the dot lines up with the front sight. Then withdraw the rod slowly, allowing it to rotate with the rifling. When the dot on the tape has rotated1/4 turnput another mark on the rod right at the muzzle. Measure the distance between the dot on the tapeand the mark on the rod, and multiply that measurement by 4. (For example, if it rotated 12" in 1/4 turn, when you multiply that 12" by 4 you find out that your rate of twist is 1 turn in 48".) Now youknow your rate of twist.

Eighty five grains of T7 FFFG is a pretty hot load for a 50 caliber ball. I would not expect great accuracy with that load under a patched ball. I'll bet it's blowing the hell out of those .010 patches. I suggest you try Pyrodex before youswitch to a musket nipple. I suspect your ignition problems will go away and youget better accuracy.

When you say "sometimes it takes a couple of hits to go off",do you mean the cap takes a couple of hits before it pops, or you have to pop a couple of caps to get to load to ignite. If the caps take more than one hit to pop you probably have a nipple problem. Get a new nipple or dress the one you have with a file.

EDIT: I see Cayugad and I were typing our replies at about the same time. I hereby bow to his wisdom.