View Full Version : HK USP jamming/malfunctions
About a month ago I purchased a police trade-in USP 40S&W fullsize and it came with a bad mag. It was marked on the bottom "missfire" and yet the LGS didn't hesitate to sell it to me.
The USP has a date code from 2002. My initial inspection revealed some grime on the feed ramp and in the bore. It cleaned up really nice and there is not really any visible wear on it. There is not any significant holster wear on the slide either.
The bad mag marked "missfire" would cause a malfunction every 30 rounds or so. I brought it back and they gave me a replacement mag. Long story short, this mag won't catch unless I use alot of force.
I was using my newly purchased "good" mag today and put about 150 rounds through it and on the last round of my 2nd magazine, it just went click. I thought I miscounted until I looked at the frame and saw the slide was not locked backed. I racked the slide and the bullet popped out as normal. I reinserted the round into the magazine and it fired flawlessly.
It's also worth mentioning that during the magazine that initially jammed, the brass was flying towards my face which is out of the ordinary compared to the other times I've fired this gun.
About 4-5 magazines fired later, I had another malfunction. This time, it looked like a ammo issue. The back of the round/primer was just pushed in. The rest of my rangetime with my USP went perfectly.
Any suggestions? Extractor issue maybe? Should I replace mag springs and guide rod spring as it's a used police trade-in?
On ANY used gun, I strongly counsel automatically and immediately replacing before use recoil and magazine springs at a minimum (other springs/components may be advisable to replace dependant upon the gun concerned/usage) unless you are in complete knowledge of the guns history and usage (and even then, I'd still replaced 'em).
Look, you simply in most cases don't know how, and/or how much the used gun has been used. It's cheap insurance to simply replace springs from the get-go; if gives you essentially a clean sheet of paper start, and lets you diagnose other issues more effectively if they crop up.
You also might wnat to contact the manufacturer (or knowledgeable forum members/armorers) to find out what the recomended preventive maintenance intervals are for specific components, and apply that.
Best, Jon
I would say that it definitely needs a new recoil spring and start with a brand new magazine, not one that they gave you from a stack of trade-ins.
What ammo are you firing?
Have you tried more than one brand?
I was shooting a mixture of Federal 180gr and Winchester White Box 165gr both times.
Does this happen with any other magazines?
I am not sure how a mag can induce a misfire. I can see failures to feed, but if the round feeds and the gun is in battery a misfire or light strike shouldn't be due to the mag. Have you cleaned and lubed the crap out of the trigger/hammer mechanism. Definitely clean the firing pin channel. If it sat around for a long time it may have some gunk built up that's causing issues.
The first magazine that came with it marked "missfire" i can confirm. The other mags, I don't know. One mag won't catch, the other one still had misfires but catches fine when racking.
As well as springs, the gun needs a deep cleaning. Firing pin channel, extractor groove and spring etc. After a detail cleaning, properly lube the gun and try it with a new mag.
gtmtnbiker98
01-26-12, 09:34
Contact HKI and send it back. They'll go over it and replace any out of spec parts for nothing. They will take the guessing out of the equation.
El Vaquero
01-27-12, 00:18
I would still look into buying new mags, unless your okay using them as range only mags. I once purchased around 5 trade in used mags and even after replacing the springs in them they still didn't fit quite right. Because the used mags are polymer and had most likely been kept fully loaded they had a bow to them and would sometimes not eject properly. New mags would fire 100% all day long.
Other than that, I would say a good cleaning and new mags and you should be good to go.
Thanks for the advice guys.
I broke my piece down to clean out the extractor, firing pin channel, etc. There was a significant amount of gunk around the extractor and the claw. Night and day difference - this could have very well been the issue.
I then took the firing pin out to check that out and clean in there. As I attempted to put it back together, the ****ing firing pin block spring when BOING! right across the room. Needless to say, I have not found it!!! :cray:
Not to worry, I ordered it online. Here's what I ordered to "refurbish" my USP:
- 3-pack of +10% Wolf Mag Springs
- Wolf recoil/guide rod spring
- 1 brand new HK magazine
- New style firing pin
- New style firing pin block
- New style firing pin block spring
- Old style firing pin block spring
Costed me roughly $100 for everything. Not bad. I can't wait to put this bad boy back together and see how it runs. I expect good things.
Thanks again for the advice.
So I know this is an old thread now but I figured I'd do a little update on what happened here since I ordered and have installed the parts I needed (and FPB spring that I lost...)
I replaced my mag springs with the Wolff +10% and cleaned out the extractor area real nice. There was a bunch of gunk caked on the extractor claw. I'm guessing this was the problem as it looked like it had been on there for probably years. I could tell it had never been cleaned in its 10 year existence.
So I ordered the new style firing pin block, firing pin, springs, etc however I've been waiting months for the new style firing pin block to come in stock anywhere at all!! Oh well, I'll get the newer firing pin in there sometime soon hopefully. I have a Wolff guide rod spring that I purchased too but I think I'll be keeping it as a replacement/backup part.
So anyways, I have put at least 300 rounds through my USP since I did the detailed cleaning on the extractor/firing pin channel. Very happy to report that I have not had any kind of malfunction or brass being thrown in my face since! Overall, it was very easy for my first time and I could do it again in a few minutes flat. I think that a complete break down and cleaning of the slide assembly is necessary on any police trade-in.
Anyone who has a USP and has never bothered - It's easy and definitely worth the few minutes it'll take.
On a side note, if anyone has a new style firing pin block they can spare then help a brother out! :D
Bad Medicine
03-13-12, 10:43
DJ, great to hear that you got your USP up and running! Read through this thread suprised you were having any issues at all! I own a USPf .45 and all the reading I have done about they USP series is nothing but solid reports on how reliable and awesome of a platform it is!
DJ, great to hear that you got your USP up and running! Read through this thread suprised you were having any issues at all! I own a USPf .45 and all the reading I have done about they USP series is nothing but solid reports on how reliable and awesome of a platform it is!
There's little doubt that the USP is one of the best and most reliable handguns ever made.
I think the main issue is that my police trade-in USP had been soaking in its own shit for a very long time. Mainly the gunk in the extractor claw is what can effect its function if it gets out of hand; being a a 2002 model and so dirty when purchased.... it's somewhat understandable.. I wouldn't doubt that it was only cleaned a couple of times in a 10 year span before I took it home. I should have taken pictures - absolutely ridiculous.
The good news is that it cleaned up really nice. My brother bought his USP brand new maybe a year or so ago and he said mine looks to be in just as good or better condition.
It's a fool proof design, really. There's a reason HK is using basically the same design even now for the HK45, P30, etc. I'm a happy camper. Looking for my next HK. :D
Bad Medicine
03-13-12, 13:12
Agreed, I have my sights locked on an HK45 and HK45ct next March I am physched about it. Hopefully they never go away from what works, I have been going back and fourth on buying a Glock but their newer gens have had so many issues! I plan on staying with HK for a really long time!
There's little doubt that the USP is one of the best and most reliable handguns ever made.
I think the main issue is that my police trade-in USP had been soaking in its own shit for a very long time. Mainly the gunk in the extractor claw is what can effect its function if it gets out of hand; being a a 2002 model and so dirty when purchased.... it's somewhat understandable.. I wouldn't doubt that it was only cleaned a couple of times in a 10 year span before I took it home. I should have taken pictures - absolutely ridiculous.
The good news is that it cleaned up really nice. My brother bought his USP brand new maybe a year or so ago and he said mine looks to be in just as good or better condition.
It's a fool proof design, really. There's a reason HK is using basically the same design even now for the HK45, P30, etc. I'm a happy camper. Looking for my next HK. :D
Pistol Shooter
03-13-12, 15:50
Thanks for the update dj, so many posters with problems never follow up.
Very glad to hear you got your USP running as it should. :smile:
I have a few HK handguns and they all run like Swiss watches.
Get to the range and enjoy your new pistol.
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.