Funshooter, you mention your bullets are "close to pure lead". What is your alloy mix?
I ask for three reasons:
1) pretty much all alloys are "close" in composition, but the resultant can have wildly varying properties. A little bit of wheelweight or linotype skews affairs quickly.
2) You didn't quench. Lordy, I hope not. The .45-90 is not the place for hard bullets at all. Your alloy of choice should start around 30:1 Lead/Tin
3) Different alloys will shrink at specific ratios of dimension after cast. Pure lead shrinks the most, heavily alloyed (lino/WW) the least. If you have a bullet mould meant for soft lead and cast with alloy, the bullets will be oversized from the start.
If you haven't visited this site, do so, read and learn:
http://www.lasc.us/CastBulletNotes.htm The day I was casting and sizing was a ruff day nothing was going well.
I found out that I had to get the lead up over 850 deg. before the heavy frosting of the bullets would go away. That took a while to figure out.
I did not quench them. I let them slow cool and burned my fingers several times thinking that they were cool enough to sort the good from the bad. (Big heavy slugs take some time to cool off)
I started heating up my lubber and pushed and pushed. Crushed some gas checks in the process.
When I did force some threw. The lube heater got so hot that the lube started burning my fingers. It was like water coming out of the machine.
Still trying to get something done I kept forcing the until I smunched a slug so bad between the heat of the lubber and my pressure against it I do not think that it would go threw a 60 caliber barrel .
At that point every thing stopped.
I need to re adjust my lube heater and I sent the dies back to have the manufacturer look at them and make the proper adjustments.
I do not know the actual alloy that I have but it is very soft for me to smash them like I did.
Time to take a step back and take a breath before the dies come back.
The guy who made the dies said that he uses straight Alox on a few bullets just to get things started right. This is the first time I have tried sizing large heavy bullets. I have a lot to learn.