[USPc9mm]

i went to the range yesterday with my USPc 9mm for the second time and had at least 4-5 stovepipe jams and 2-3 failures to lock the slide back.

the stovepipes happened with the $10 10round cdnn magazines. the jams didnt happen consistently but enough to cause me a little bit of concern. this was the first time i had used the new mags.....

the failure to lock the slide back after the last round occurred with the factory 13rd magazines at least twice.

what gives? are both of these mag springs problems?

btw, i was using WWB ammo from walmart and have never had this problem before with the ammo or any other gun ive shot.

 

[ironchef]

Hmm, strange to hear with Winchester White Box Ammo. What is the date code of your USPc 9mm? Did you get it new? If so, did you clean it first before going to the range the first time around? Did you clean the gun after your first session at the range?

I have CDNN 10 rounders (thank you NYC) for my KI USPc 9mm in stainless. Haven't experienced any hiccups with WWB, Fiocchi, American Eagle, Speer Gold Dot, etc.

 

[rohardi]

THe failure to lock back on the last round could be due to you riding the slide release with your thumb. That's the first thing that comes to mind.

 

[mp5a3]

Wow, Ironchef I'm sorry to hear that. I guess NY is just as bad as CA. You should come here to Texas, the gun laws are great.

 

[mp5a3]

THe failure to lock back on the last round could be due to you riding the slide release with your thumb. That's the first thing that comes to mind.

I did that w/ my Sig 226. I kept wondering why the slide wouldn't lock.

 

[2020]

Change your mag springs to Wolff+10%. All will be well.

 

[USPc9mm]

the date code is AH. i got the gun new and properly cleaned it before and after the first shooting.

im pretty sure i wasnt riding the slide release with either thumb. Ill give this theory some examination next time at the range though.

the problems seemed to be specific to the type of magazine used, Factory vs. Aftermarket.

 

[sniper1]

Are you using promags? If so that is your problem!

 

[ironchef]

The $10 ten rounders from CDNN are factory HK ten round mags, at least the ones I've got are. Again, no hiccups in 9mm, .40, nor .45. Almost all of mine are CDNN purchases.

 

[Kost]

Check your grip on the pistol, make sure your thumb isnt close to the slide lock - proper gripping on the pistol should leave your thumb well away from the slide and all levers. Pretty unlikely that multiple brand new mags are causing the problem. Its probably your grip, hold the pistol properly, that may take care of this issue.

At the range this is only a head ache...in a real gun fight for your life...
:320000:

 

[F22_RaptoR]

Try stretching out the mag springs, then firing off some rounds (making sure your not hitting the slide release) and see if the slide locks back.

If it does, then most likely the mag springs are the cluprit.... They are the BANE of the whole USP series, they should be spec'ed much thicker and stronger, but never were. Cure is Wolff +10% springs. (or you can take a chance with HK replacing them, but your likely to get ones with equally lame springs)

 

[Dumak]

The slide not locking back after the last round is a sure sign of worn mag springs.

As others have said, get the wolf replacement springs.

 

[kartar]

I agree that the mag springs could be the problem. The wolf +10 mag springs are what I use, though I didn't have any problems with the factory ones. Also it's possible that the WWB ammo doesn't have enough power to completely cycle the slide. My favorite is Blazer Brass but others also have more power than the Winchester.

 

[ColtM1911A1]

Change your mag springs to Wolff+10%. All will be well.

ditto -- change out the weaker springs as the first attempt to fix the problem. From your description, I would certainly say the factory springs are the problem. Cheap fix and, IMO, if you replace, try to install the chrome/silicon product versus standard wire; they will probably be the last time you ever need to change them -- sources: ISMI, Sprinco, and a few others I can't recall right now...good luck

 

[H&K 4 LIFE]

With a brand new AH date coded USP I find the weak mag. spring theroy to be unlikely. I too am guilty of riding the slide-lock from time to time and this is much more likely the culprit of no lock up after the last round.

As for the stovepipes, try some different ammo and see if the problem persists. I have never had any real problems with WWB 9mm except for the occasional factory defect in a single round.