I forgot the proper term, but I am having problems with my USP 9c staying open after the last round. It is not all the time, but more frequent then I like. I have about 1200 rounds through it, and I am using American Eagle 124gr FMJ, and used 500 rounds of Olympic 124gr FMJ. Any suggestions? I have not had any other problems. Thanks.

Check your magazine spring tension. With only 1200 rounds through it, that shouldn't be a problem, but it's the magazine follower running up against the slide stop that holds your slide open after the last round goes downrange. Also check that your slide stop moves freely through its full range of motion, in other words that it's not boogered up somewhere in there and no matter how hard the follower pushes it won't move.

Does it happen with all your magazines, or just one of them? Are your magazine followers chipped or broken? Just ideas...

Have someone stand on your left and watch you shoot. See if your right thumb isn't riding up and touching the slide release. If it is, that may be your problem.

Grab a magic marker and number your magazines. See if it happens with only one of them or both.

My money though is on my first suggestion. Been there, done that and got the t-shirt.

Jarhead,
Thanks for the reply, I am going to check out the mags today. Also next range trip I will mark the mags if it happens again see if I can find some consistancy. 2 of the 4 mags are mail ordered H&K's but that is the only variable I can find. The mags seem fine in appearance, but I will check it out. I also clean my mags but if I was not assemblying correctly they wouldn't work at all?? I have to re-check that too. Thanks again!