I don't load for an in-line I load for a sidelock. Whether that would make a difference in the purity of lead I am not sure. As for the mold, I use a $17.95 double cavity LEE R.E.A.L. conical mold. I have them in .490 roundball, 300 grain (54 caliber), 380 grain (54 caliber), .530 RB and .535 RB.

I got my hands on an old cast iron pot at a flea market for about $2.00 and I use my turkey cooker stand as the smelter. I fire that up and put an old grate off a stove on the platform and the pot sits right on that. After the lead is melted, I drop a little bees wax in it to burn off the crud, scrap as much of anything else off, and then oil up the mold. The first few you check for flaws until the mold gets hot. After that you can turn them out rather fast. The conicals are real accurate out of a 1-48 twist. I am not sure what they would do in a 1-28 twist.. Good Luck