HK Slide Problem
- Thread starter VMUTH
- Start date
I know the difference.
The old .40F is a friend's, so I don't know the date code, but it has standard (non-polygonal) rifling and a non-rubberized hammer. It's old, and it drops the slide on a firm magazine insertion.
I do have a newer pair of USP40F pistols, manufactured 1998 and 2000, and my brother and a friend each have 40F stainless pistols dated 1999 and 2000 (I think), and they all drop the slide on a firm insertion. These are not first generation.
I also have a 2001 USP9F, which drops the slide, and a 2001 USP45F, which does not. A friend has a 40C, another a 9c, and neither of them do it.
No change in their behavior between 10 round or full-capacity magazines, both LE only and civilian.
According to your explanation, I've seen at least five late model USPs do something they don't.
Perhaps your pistol doesn't do it, but it is the norm for full-size 9mm and .40's in my experience. Where did you hear that only first generation pistols do this?
Morgan,
"I know the difference ... it has standard (non-polygonal) rifling and a non-rubberized hammer."
...and a non-captive recoil spring, and different DA/SA pull, and no half cock notch, and different slide lock, and a slightly different mag release.
"Perhaps your pistol doesn't do it, but it is the norm for full-size 9mm and .40's in my experience. Where did you hear that only first generation pistols do this?"
AFAIK HK modified the the slide release and the slide lock spring on the later models. For example compare the hook (sorry for my english) of the slide lock on your pistols. If you have the simple triangular hook, that's an older, 1st gen design. The newer is more curved.
And again, not just my USP9F and USP40F is NOT dropping the slide when slamming in a mag. I test shot almost the whole USP line (for www.kaliber.hu), brand new guns, out of box, no dropping slides. No such occurences with any of my (european) IPSC shooting buddies with Expert, Custom Sport, USPF pistols. No such occurences with the Compacts. No complaints from the LE guys who tested USP9F/USP9C for our government. The possible solution I can think of (as I said before) is older parts in your pistols sold by HK Sterling...
And again, there is not even a word about this in the HK USP Manual No. 986451, printed in Germany.
"I know the difference ... it has standard (non-polygonal) rifling and a non-rubberized hammer."
...and a non-captive recoil spring, and different DA/SA pull, and no half cock notch, and different slide lock, and a slightly different mag release.
"Perhaps your pistol doesn't do it, but it is the norm for full-size 9mm and .40's in my experience. Where did you hear that only first generation pistols do this?"
AFAIK HK modified the the slide release and the slide lock spring on the later models. For example compare the hook (sorry for my english) of the slide lock on your pistols. If you have the simple triangular hook, that's an older, 1st gen design. The newer is more curved.
And again, not just my USP9F and USP40F is NOT dropping the slide when slamming in a mag. I test shot almost the whole USP line (for www.kaliber.hu), brand new guns, out of box, no dropping slides. No such occurences with any of my (european) IPSC shooting buddies with Expert, Custom Sport, USPF pistols. No such occurences with the Compacts. No complaints from the LE guys who tested USP9F/USP9C for our government. The possible solution I can think of (as I said before) is older parts in your pistols sold by HK Sterling...
And again, there is not even a word about this in the HK USP Manual No. 986451, printed in Germany.
I'm afraid all this intense exchange of ideas may have turned-off Mr. Vmuth away! He hadn't even replied to all our posts since... 
I guess that basing from all the previous posts, we must have to agree to disagree on this one. I wouldn't want my favorite firearm to be involved in this kind of inconsistent behaviour.
Vmuth, I guess the best thing for u to do is to consult the nearest HK armorer, and have him take a look at your piece. He'll know what to do.
Stay safe,
New_comer
I guess that basing from all the previous posts, we must have to agree to disagree on this one. I wouldn't want my favorite firearm to be involved in this kind of inconsistent behaviour.
Vmuth, I guess the best thing for u to do is to consult the nearest HK armorer, and have him take a look at your piece. He'll know what to do.
Stay safe,
New_comer
on my usp9c, when i look inside, i can see the exact part of the slide release that the mag is hitting, causing the slide to lock back when the mag is empty... but i don't think this is related to the feature in question... in fact, i can get it to go forward by gently insertig the mag first, then slamming the bottom of the mag hard... same effect as slamming it in in one motion. there's a small fraction of a millimeter (vertical) play when the slide's already in... pushing hard doesn't work. pushing fast does. it's not force, it's power. how quickly you appy the force. my theory: smacking it hard must cause the entire gun to jerk in the direction of the hit, while the slide release's mass and spring resistance keep it stationary. so the "system" is the gun minus the slide release. the system moves one way, the slide release is stationary. this is equivalent to the slide release being moved down on a stationary gun.
date code KI (98).
date code KI (98).
That's just the point. That is, if you SLAM it hard enough, by virtue of the impulse on the entire gun body , it is as if the slide lock lever remained motionless relative to the slide. In the other TFLr's accounts, you could bruise your hand and not be successful in disengaging the lock, as in my unit. But Vmuth's is different, as could be read in his only post. There lies the difference, IMO.
REgards,
New_comer
PS: BTW, satyen119 - WELCOME to TFL!
REgards,
New_comer
PS: BTW, satyen119 - WELCOME to TFL!
ZipTieNinja
New member
The slide catch on most guns is spring loaded so that it remains in the the disengaged position. A piece of the mag presses the catch up, with more force than the spring on the slide catch. In my Beretta, it is the piece the the botton bullet rests on. When a full mag, or one with only on bullet, that devise in the mag, or on it, is no longer holding the slide catch. The friction from the slide pressing against the catch, is what prevents the catch from moving down, and the slide closing. When you slam a mag in, the vibration causes the slide to move back, or at least removes some tention, and the slide catch spring is able to push the catch down, and the slide closes.
I have a Beretta 96 that does it if you really slam the mag in. I have to slam it in pretty hard to get it to do that. I also have a Ruger Mk 2 Target pistol, and the mag has a button on the outside that pushes the slide catch up.
Hope that made sense, physics is a hobby of mine. If the slide is releasing with too light of an impact, a stonger recoil spring could solve the problem, but may cause others... I think it is a QC issue. Thats a tight tolerence to try to hold, and the problem could be that the mating pieces of metal are too slick.... Take the gun to a gunsmith and ask him if he can do anything. Good luck, and just remember to first rule of gun safty, always keep it pointed in a safe dirrection. Stay safe.
P.S. I thing this is what New_Comer and Satyan119 were geting at.
I have a Beretta 96 that does it if you really slam the mag in. I have to slam it in pretty hard to get it to do that. I also have a Ruger Mk 2 Target pistol, and the mag has a button on the outside that pushes the slide catch up.
Hope that made sense, physics is a hobby of mine.
If the slide is releasing with too light of an impact, a stonger recoil spring could solve the problem, but may cause others... I think it is a QC issue. Thats a tight tolerence to try to hold, and the problem could be that the mating pieces of metal are too slick.... Take the gun to a gunsmith and ask him if he can do anything. Good luck, and just remember to first rule of gun safty, always keep it pointed in a safe dirrection. Stay safe. P.S. I thing this is what New_Comer and Satyan119 were geting at.
Kirk Keller
New member
I've tried
... to repeat your problem on my USP .45 Compact to no avail. The only way I can get the slide to release is to press the slide release.
... to repeat your problem on my USP .45 Compact to no avail. The only way I can get the slide to release is to press the slide release.