I don't know anything about USPs but crud around an extractor can make it difficult for the cartridge rim to slide up into the bolt face as the slide strips it from the magazine. This could cause an alignment problem when it hits the feed ramp.
In pic 1 and 2 the round is no where near the extractor, don't look like the case head even came out of the magazine so don't think that is the problem. Looks like a low power round that didn't push the slide back far enough to pick up the next round. Limp wristing ?
NRA Certified RSO
Be where your feet are
I dont like limp wrist either, but I just dont have an easier way to explain it.
The only thing I managed to do with my HKs in 45 caliber to similarly replicate the issue 100% of the time is that the slide is catching on the notch the extractor uses (instead of the back of the casing) and is blocking the back of the round from seating properly even though it can send the round forward. I'd presume either something is up with the recoil spring of your USP or that you're limp wristing. Next time it happens, double check to see if you can see the slide resting on the notch on the round that the extractor uses.
Last edited by sixtwosix; 12-17-2017 at 02:08 AM.
I unfortunately do not.