Some notes, shooting with the Minies...
1. Dont overlube them. The nice thing about using Minie-ball as your bullets is that they expand at the base when you fire, so the skirt contacts the rifling. The major reason for rifling in black powder guns is to give the gunk somewhere to go, not to provide better accuracy. With the twisted grooves in the barrel, the crud leftover after the shot goes down there and leaves the barrel itself free of obstructions longer, so you can get more shots fired before you have to clean it. All you want is just enough lube to fill those grooves in the skirt. When the skirt expands, the lube will catch the gunk in them from the previous shot, and carry it out the barrel, helping keep the barrel clean enough to continuously fire. If you put too much lube on the bullet, it wont really do any harm, but it will make more of a mess. And if it gets down into your powder, it can cause clumping and uneven fire.
2. After firing, remove the percussion cap, place the stock on the ground, and blow into the barrel. Dont want to chance pouring powder in for your next shot and having a spark glowing down there in a little lump of powder that didnt go off with the rest. Good way to lose some eyebrows.
3. When you put the Minie into the barrel, you dont patch it like you do a round ball, and you certainly dont have to ram it. You dont want to accidentally deform the bullet. Just use the rod and lightly tap it to make sure its all the way down and didnt catch on anything. The Minie is designed to DROP in, because of the skirt expansion. It will be plenty large enough when the explosion starts it down the barrel.
4. If you decide to cast your own, check with tire stores for used wheel weights. Great source of free lead. Be cautious casting Minie-balls though, because of the way they need to expand. The skirt needs to be just right, and there should be "cuts" on the side where the lead is VERY thin (this helps with the expansion of the skirt). Try to find some folks who already make their own if you are serious about it, and watch how they do it.
As noted already, if you cast your own lead, make sure you have proper ventilation, good equipment, and proper protective gear. A good leather apron is priceless for this kind of work. Lead melts at 360 degrees. You dont want to slop that on you.
Enjoy your rifle.
They are quite accurate and hit with LOTS of power.