What is your barrel groove diameter? A cast bullet has to fit the throat on a 1911 .45 acp, maybe .001" larger than the groove diameter. Most 1911 .45 acp are .451". My experience is that a Lee mold may run a little larger than it is supposed to, and if so, you may need to size it down. My experience is best accuracy comes with unsized bullets. I have some pistols that have chambers so tight they would not chamber a cartridge loaded with a bullet big enough to fit their oversize groove diameter. There are also pistols where the groove diameter is so oversize the bullet is not going to fill them, and cast bullets will result in incredible Leading.
I have no experience with powder coat.
If the ID of your cartridge case is really small, and your bullets soft, the cartridge case can size down a bullet that fits the groove diameter such that it becomes too small, resulting in Leading.
When casting bullets, a couple percent Tin is your friend, increasing Lead fluidity and bullet fill-out.
I have found HP38, which is just WW-231, to be an excellent powder in .45 acp.
I believe you are saying you have Lee Liquid Alox as your lubricant. Lee Liquid Alox is one of a family of Calcium soap products of the Lubrizol Corporation, which bought the old Alox Corporation long ago. Lee Liquid Alox is Alox 606-55, indicating it is cut with mineral spirits:
https://www.thegearboxguys.com/data/ALOX606-55pds.pdf My experience is that it frequently feels a little tacky after it drys, and people who find that offensive will add more things to it, or dust the lubricated bullets with something to remove the tackiness. I have noticed that it can build up on reloading equipment, which can do dangerous things like incrementally increase seating depth until it is dangerous, but Dillon Seat dies are designed to allow cleaning without losing adjustment. Be careful with the term "Alox", as there is another older concept in bullet lubrication where a greasy lubricant that is 50% Alox 2138F/50% Beeswax is pushed into deep grooves on the bullet.