First off I have to say that though I've been handgun reloading for about fifteen years I have no experience loading the moly coats. Have you checked how much you're belling the case mouth? Sounds like too much flaring for bullet seating. When you crimp you may be leaving some of the case bulged from the belling.
Cartridge OAL for the 45 ACP is listed in several of my books as 1.275".Though that's not necessarily the case with your particular swc.That's part of the fun of reloading-experimentation, seeing what does and does not work well. Case max. length is listed as.898".
Another option may be the bullet itself. Not sure about the USP (I'm envious BTW) but most 1911 style weapons need some polishing of the feed ramp before they digest anything that does not have a similar ogive(sp) to hardball.
[This message has been edited by fal308 (edited 12-10-98).]