Molding setups are cheap, if you aren't trying to mass-produce. You can melt lead in a small iron pot on your stove, but if you share a residence with those who aren't enlightened enough to understand your need to do this, a basic electric melter runs about 35 bucks new.
$25 for a mold, $5 for a ladle, and whatever it takes to get some gloves and a surface that doesn't burn easily (we used to use asbestos gloves and asbestos boards, but those days are, sadly, gone now -- asbestos works GREAT if you don't get cancer).
The problem is getting the lead for a decent price, now. Wheelweights have been a common cheap/free source for alloyed lead (melt, pull out the steel clip with pliers, and mix with pure lead in the melter to get the right hardness), but those kinds of wheelweights are going the way of the buffalo, I think. Anyone know if you can use what they've sticking on alloy wheels these days?
Bear in mind, this isn't the fastest process, and you have to get your technique down. At first, you'll be dumping a good number of bullets back into the melter.
I last did it for .45-70. It wasn't bad, just got into a rhythm and made 100 of 'em. But we were only going for enough accuracy to hunt buffalo, and you don't need sub-MOA to hit a buffalo.
Lyman sells bullet sizers and other fancy things to make really perfect bullets. The crazy 1000-yard BPCR guys have their tools and tricks, of course.
To use lead bullets in, say, a .30-06, you have to keep your velocity down a bit. I forget the magic number you don't want to exceed. However, a lot of reloading books, especially older ones, have spec's for lead loads, even for (relatively) modern cartridges. There probably wouldn't be much point to casting centerfire .22 bullets, but for a round that doesn't
need to leave the muzzle faster than 3000 fps, cast bullets can make sense, sometimes, maybe...
Also, you will have to clean the lead from the barrel now and again. However, I've done it with Xylene and wads of paper towels. It's not hard; it's just something else you have to remember to do.
It's a whole other (messy) adventure...
