I get very good accuracy with minies in my Springfield with 35-40gr. FFFg. Bullets must be no more than .002 less than bore size, preferably .001 under. Accurate, but pretty wimpy. I can watch them fly to 100 yards if the light is right. It also shoots very well with a patched .570" ball and 80gr. FFg. Much faster and flatter, more power but not as fast to load as the bullets are.
For lube I use Emmert's - 45% beeswax, 45% Crisco, and 10% Jojoba oil. I melt it in a little pan (tuna fish can) and dip lube the bullets, holding them with a pair of smooth pliers. Dry on wax paper. No wads under the bullets, just load and shoot. Don't get the lube too hot.
Supposedly Treso makes nipples with the right thread to fit muskets that take #11 caps. I haven't found any yet, but did get 1000 musket caps from Powder Valley so I'm set for a while.