Have seen this before and what we found was the sizing die was not fully sizing the cases.
The carbide sizing die was not fully sizing the case because it was bulged. The carbide die was part of the problem because of its inside taper. The distance of the inside taper to the base of the seating die was enough that it would not size out all of the bulge.
Some pistols are notorious for bulging cases. Lee makes a bulge buster die which will take care of things.
I thought I might add to watch primer pockets when reloading 45ACP. Seems some manufacturers are making brass with small primer pockets.