First malfunctions with my USP

[Capp325]

I have several thousand rounds through my 9mm USP and have not had a single malfunction of any kind - until today. While going through two boxes of Winchester Winclean 147 gr, I experienced the following problems:

1) One double feed (the empty case did not fully extract and the next round was stuck beneath it)
2) Two suspected "near double feeds" - the gun cycled, but it felt weird - as if the gun was having a hard time feeding the round.
3) One light primer strike

Do you guys think that I came across a faulty ammo batch? I haven't had any issues whatsoever in over two years of shooting this pistol, and all of a sudden I get 4 problems during a single range session. This just doesn't add up. The gun is fine mechanically and nothing is broken as far as I can see.

[IDontHaveTheTrunkSpace]

I've never had good luck with winclean in any gun ive used it in. I think its crap.

[Shakey]

Try a box of different ammo before you consider the pistol at fault. Also use a different mag just to rule that out. I use Winchester white box 115 gr FMJ all the time and have never had any problem with it. I've never used 147 gr Winclean, but the USP 9 feeds 147 gr Winchester Ranger SXT (LE) without any problems at all.

[gunut45]

The ammo for sure. A bad mag may cause double feeds but it will not give you light primer strikes.

[bhale187]

Try some new ammo next range session, if you have another double feed mark that mag, it is usually the problem. But as gunnut45 said, light primer hit ain't the mag.

[Tabsr]

Clean it well and try again, most likely the ammo.

[mew]

I find my malfunctions are almost always ammo related ie; cheaper ammo. I shoot mostly blaser brass or blaser alum. and find it either works consistently or it doesn't. Most of the other "cheaper" Win. Rem. or whatever else is based on your pistol/mag combo and whether it will shoot it or not. My Sig 220 and Beretta 92 will shoot anything I feed it while my Colt NM will only consistently shoot FMJ of whatever brand. It is the HP ammo all the pistols feed unreliably and you have to shoot all of them to find the one your pistol likes. I have to say on the cheaper end the Blaser brass shoots the best for all my pistols. Federal Hydrashok, Speer Gold dot and Win, silvertip or lawman HP are some I shoot consistently well without failures.

[Cadillac Johnson]

If possible shoot some of it from another gun and see what happens. Do that along with the other suggestions.

[sfguard]

Try different ammo if that don't help start with the mag springs

[kingofwylietx]

I agree, the first thing I would do is try different ammo. I have not tried Winclean, but have put thousands of rounds of WWB through my USP with no issues. I have heard the WWB can have hard primers, I don't know about Winclean. If you switch ammo & have no malfunctions, your question is answered.

[Troutrunner]

For some reason my USPF 9mm didin't like the WWB so I switched to American Eagle and have over 5000 rounds without a hiccup.

TR