Geezus the thousands and thousands of 200 gr. cast semi-wadcutter H&G #68 bullets I've personally cast and/or bought and fired from various .45 ACP handguns... I couldn't hazard a guess at the numbers, though it would be interesting to know. That's a great bullet, accurate, feeds reliably, cuts good holes in paper and kills small game and varmints noticeably better than a round nose. Today I get mine from the Missouri Bullet Company with the Hi-Tek poly coating. No messy lubes and no leading. Cast bullets are great in the .45 ACP, probably 90% of the bullets that go down my bores are cast bullets. Do it right and they cost less and wear the barrel less than jacketed bullets with little muss or fuss.
EDIT: If you are getting leading from low velocity .45 ACP bullets it is probably because they are too hard. The bullet is going slow with low pressure behind it and being too hard that doesn't allow them to obturate and fully seal the bore. This allows gas cutting along the sides of the bullet base and the bullet sorta skids in the rifling smearing splashes of lead along the way. That's not a particularly great description really, hopefully you get the idea. The same alloy mix that works for a 1,400 fps .44 Magnum is most likely too hard for an 850 fps .45 ACP. And of course the opposite is true also.