USP 9c releasing mag during fire

[jck397]

Today I fired my USP Compact 9 for the first time, and had the magazine fall out during strings of fire 3 or 4 times. I believe all 4 times were with the same mag (a brand new factory mag), and usually on the 4th or 5th shot of my string. This was the first time I fired the weapon, which I bought NIB. The only modifications were installing a factory extended mag release, and converting the weapon from DA/SA w/safety to light LEM. I have a lot of experience shooting Glocks, M&P's, and SIG's, but only a few hundred rounds through rental H&K's over the years. My grip was my usual high grip. The ammo used was Winchester Super X 147 gr. and WWB 115 gr.

Has anyone else experienced anything like this? Is my grip causing the extended mag release to bump during fire? Is there anything else I should be looking at?

Thanks!

(50 rds. Winchester Super X 147 gr. and 50 rds. WWB 115 gr.) out of my NIB H&K USP Compact 9mm. The weapon is stock, except I installed a factory extended mag release and converted it from DA/SA w/safety to light LEM.

[MitchK]

Some folks do have an issue with their finger hitting the release under recoil. Make sure that's not whats happening before you do anything else.

[jck397]

Some folks do have an issue with their finger hitting the release under recoil. Make sure that's not whats happening before you do anything else.

Looking at my finger placement during dry fire, it doesn't look like that's the culprit. The meaty part of my middle finger between the second and third knuckles does push up against the release quite a bit, though.

[45C]

Is the mag seated properly? Mag release installed properly?

[jck397]

Is the mag seated properly? Mag release installed properly?

Yes and yes. I seated the mags firmly and when I was cleaning it after shooting checked both mags by tugging on them and wiggling them when in the weapon--they stayed put.

[Sensei]

Who did the install on the extended mag release and was it done properly?

[SkiDevil]

I own a USP 9 compact as well. It has been utterly reliable.

I would suggest re-installing the original mag release on the pistol and then shoot it again. Then you should be able to isolate the problem.

[JW5219]

I would suggest re-installing the original mag release on the pistol and then shoot it again. Then you should be able to isolate the problem.

This ! I believe you will find it's your grip with the extended mag release causing your problem. Good luck with it----

[mndang]

I own a USP 9 compact as well. It has been utterly reliable.

+1 on this.

[Kchen986]

A lot of people at HKpro reported the same issue with the P30/HK45 series of weapons, due to the larger mag release. I think your problem lies in the same area--accidentally bumping the mag release under recoil.

[jck397]

Appreciate all the feedback. I've reinstalled the stock mag release, and hopefully I'll get a chance to shoot it this weekend. I'll report back as soon as I do.

[Mak8080]

Fantastic, please let us know. Just a thought, you could try to take a video of yourself to see what exactly is happening with your grip, etc.

[jyo]

Intertesting thread---I currently own several HKs, including a 1994 USPf pistol that came with the larger release as standard---also a P30S, P2000, 45C, USPc 9mm, etc. None of them has ever had an issue while firing---some have the smaller release (they will ALL have the larger release soon) and some have the larger---all mags stay put during shooting. Certainly let us know how shooting goes with smaller release back in...