To melt the lead I used a Lyman Big Dipper furnace, which I got as part of a kit that also included a lead dipper, an ingot mold, a copy of the Lyman Cast Bullet Handbook, 4th ed., and three kinds of bullet lube. (Right now the only lube from the kit that I have a use for is the Alox, which I used for fluxing the lead. I gave the Orange Magic lube to my brother, while I'll give the moly lube to a friend.)
The mold is in good condition for its age but when I got it the sprue plate retaining screw was stuck. After a few weeks soaking in Kroil I was able to remove it this morning without too much effort. I think it was just a crud buildup because there didn't seem to be any rust on it or in the hole in the mold block when I removed it.
To warm the mold I let it sit on the pot as shown above, while the lead was melting. I then got it up to a good temp by casting some bullets, which wound up back in the pot.
This was the first time I'd cast bullets in a couple decades, so I'm pleased with today's output. Before taking the picture a bunch of wrinkled bullets from when the mold was too cool had gone back into the pot.
I measured a few with a digital caliper and they seem to be dropping at about .425 to .426, which is on the small side. However, they may still be usable in my rifle when loaded on top of black powder. Because they are soft, the sudden jolt from the black powder charge may bump them up to fill the throat and grooves. The only way to know for sure will be to load them up and try them.
However, I suspect that I will need to add some tin to my lead. All cast lead bullets shrink a bit when they cool but adding tin not only hardens the lead, it reduces shrinkage.