Help Me Unscrew Up My HK USPC...

[SteyrAUG]

OK, I came here seeking a simple "how to" replace my bobbed hammer with a non bobbed hammer on my USPC. And somebody made the the incredibly bad suggestion that I follow the LEM installation topic as my guide.

And now my USP doesn't work at all. With the slide OFF in functions in DAO and when the hammer is back pulling the trigger does NOT release the hammer. Please keep in mind I didn't replace ANY PARTS except the hammer and I used a DA/SA hammer. I also didn't do any of the modifications to the trigger and stuff like that.

But obviously as the topic was how to do a LEM conversion, there were a lot of things I didn't want to do and some I did so it was very confusing.

Also something is terribly wrong because I can't even put the slide back on the gun for a complete assembly.

Are there any knowledgeable people who can figure out what I did wrong?

[AviatorDave]

Do you have the USP armorer's manual already?

You can get it here:

http://www.stevespages.com/page7b.htm

The disasssembly instructions are in text predominantly, but it does explain the correct order and how to take it apart.

[SteyrAUG]

Do you have the USP armorer's manual already?

You can get it here:

http://www.stevespages.com/page7b.htm

The disasssembly instructions are in text predominantly, but it does explain the correct order and how to take it apart.

No and my computer can't open pdfs. Also I think I need more than text to correct this one. I can do HK 90 series and MGs in my sleep but when it comes to USPs I'm a novice.

And I'm certain I put it back together the same way I took it apart so a manual isn't gonna tell me which one I did wrong.

Here is the patient.

http://img530.imageshack.us/img530/5792/00000000021fo0.jpg

[AWD]

So, it works in DA and not SA correct? If it has a decocker, does that work by any chance? What is preventing the slide to not go on, perhaps the disconnector? Sorry, probably not much help here.

AWD

[SteyrAUG]

So, it works in DA and not SA correct? If it has a decocker, does that work by any chance? What is preventing the slide to not go on, perhaps the disconnector? Sorry, probably not much help here.

AWD

Decocker works. Fires in DA but when the hammer is back pulling the trigger does nothing. ANd yes something is obviously preventing the slide from going on smoothly.

[AWD]

Can you push the disconnector down, and it spring back up like normal?

AWD

[SteyrAUG]

Can you push the disconnector down, and it spring back up like normal?

AWD


Yes.

[Jonesaa]

I’ve noticed that sometimes if you dry fire without the slide on, some pins will slide out just a little (don't know the technical name, but they slide through the pistol perpendicular around the decocker area)...this could be what is keeping the slide from going on...

[MaverickH1]

I don't see the flat spring in your picture. And I should be able to see it.

If that breaks, SA may not work. That doesn't exactly explain why you can't put your slide on... unless it's caught underneath the control latch.

[MaverickH1]

Oh, and make sure your slide release is still out when you try to put the slide back on :)

When I did my match trigger upgrade, I forgot that I had left the slide release in just to have one fewer part to track down. Boy was I panicking when the slide wouldn't go on :)

[AWD]

I’ve noticed that sometimes if you dry fire without the slide on, some pins will slide out just a little (don't know the technical name, but they slide through the pistol perpendicular around the decocker area)...this could be what is keeping the slide from going on...

Dry firing with slide off... not the best for your frame and components. Unless you ride the hammer down real easy.

[AWD]

I don't see the flat spring in your picture. And I should be able to see it.

If that breaks, SA may not work. That doesn't exactly explain why you can't put your slide on... unless it's caught underneath the control latch.

I never thought about that, although he really wouldn't need to remove the flat spring for a hammer swap. I suppose one of the spring tangs could have broke off/got bent during installing the sear and/or catch? When I did the teardown on the USPc I removed the flat spring just for SG&G, all you need is a long thin needle-nose pliers (the spring has a one-way type locking tab.) Hopefully for Steyr fixing it is something easy like this...

Keep us informed man, I am curious as to the fix.

AWD

[Jonesaa]

Dry firing with slide off... not the best for your frame and components. Unless you ride the hammer down real easy.

You're right...I think i read that in the manual too, sadly, after i did it several times after buying my first HK. Just thought i'd throw it in there, he said something about SA not working and not being able to get the slide on either...

[benderx4]

From the picture, it looks like your sear axle is sticking out the the left side of the frame. Using just your thumb, you should be able to easily push this back in towards the right side of the frame so it becomes flush and allows the slide to be re-installed smoothly.

Again, this is pretty common if you dry fire and/or de-cock with the slide off.

[SteyrAUG]

I don't see the flat spring in your picture. And I should be able to see it.



Anyone got a picture of what that is and where it should be located? I'm so damn lost.

[AWD]

From the picture, it looks like your sear axle is sticking out the the left side of the frame. Using just your thumb, you should be able to easily push this back in towards the right side of the frame so it becomes flush and allows the slide to be re-installed smoothly.

Again, this is pretty common if you dry fire and/or de-cock with the slide off.

The sear axle should be sticking out of the left wall of the frame... that is what the decock/safety detent plate rides along. Push it flush with the frame and the detent plate will remove itself frome the pistol.

AWD

[AWD]

http://i301.photobucket.com/albums/nn55/AWD12345/039.jpg
http://i301.photobucket.com/albums/nn55/AWD12345/041.jpg

You can barely see, but the spring tangs are visible... one forward of the catch assy, and one forward of the sear. The tang against the sear is further aft than the catch tang (in relation to the frame.)

AWD

[SteyrAUG]

http://i301.photobucket.com/albums/nn55/AWD12345/039.jpg
http://i301.photobucket.com/albums/nn55/AWD12345/041.jpg

You can barely see, but the spring tangs are visible... one forward of the catch assy, and one forward of the sear. The tang against the sear is further aft than the catch tang (in relation to the frame.)

AWD

Well that is a rather large problem.

http://img401.imageshack.us/img401/7716/00000000023rq5.jpg

As you can see, on my gun those springs are UNDER the sear assembly and I have no idea how that happened. And when I made an attempt to remove them they seemed rather fixed in place.

How are they assembled into the gun? They almost feel attached to the frame.

[SteyrAUG]

Wait a sec, I think I just found the problem.

I think I installed the whole sear assembly without pushing the springs forward. I didn't know that was necessary but looking at the pics it must be.

[SteyrAUG]

Well spoke too soon.

http://img136.imageshack.us/img136/4637/00000000027uq1.jpg

Installed everything behind the springs and it still doesn't work correctly. And things are so tight it doesn't even function in double action and you can't cock the hammer.

Things are very, very wrong.

[nwusp45]

I think the LEM part might have messed you up, since the LEM and the traditional set-up are different. Here is a very good tutorial on how to take the standard USP a part, put it back together, etc. Good luck.

http://www.streetpro.com/usp/detail/more.html

[Backstop]

The same issue happened with my USP 45C a while back. It turned out that the trigger bar wasn't set back in place as it should have been. There is the plate (item number 20 in the illustrated breakdown I've got) that is second to the last item in on the right most side of the axle when all the pieces are installed (directly inboard of the last plate on the right most side of the axle). The notched & hooked end of the aft part of the trigger bar can inadvertently be installed in the not so correct location relative to part number 20; the second plate inboard from the right. When that happened with mine, the exact issue described by the OP happened each and every time I tried a pull on the trigger after bringing the hammer back. Mine was set-up as V1 so I can't be certain that the same plates are used with LEM. If they are, you might have a look at how the trigger bar is communicating with that plate. Solved the problem for me.

[gemarsh]

I think your flat spring is toast. After being installed behind the sear/catch, it has gone past where it want's to rest. Should never be that close to the hammer.

Easy to change, just hard to find. Gotta get to the field, but I'll look later to see if I have one on hand if you don't find one before.

Here is a page I use to help people along......

http://webpages.charter.net/gemarsh/hk%20usp%20trigger%20smoothing.html

Be Safe
Gayle

[MaverickH1]

Yes, that flat spring is rather weak and easy to break. If you pinned it as bad as you say, it may need to be replaced.

I think the flat spring is the one reason HK doesn't want people disassembling their own USP. It's the hardest thing to NOT break when reassembling.

If the leg to the right (if looking down the sights) is off of the catch, your USP won't stay cocked.

I can't see anything else from your picture that looks off.

[SteyrAUG]

I think the LEM part might have messed you up, since the LEM and the traditional set-up are different. Here is a very good tutorial on how to take the standard USP a part, put it back together, etc. Good luck.

http://www.streetpro.com/usp/detail/more.html


Man, something like that is what I was looking for when I first came here and got directed to that LEM mess.

Seems I don't have a hammer return spring. I wonder if that might be my problem.

I don't think any damage was done to my flat spring, seems ok.

[SteyrAUG]

Well I finally got it.

The link posted by nwusp45 was a great help. My main problem was doing the hammer spring last so it was coming out of alignment. When I replaced it PRIOR to doing the sear setup then suddenly my USP worked perfectly.

[praetorien]

Where did you get the hammer from? I got one from that Cddninvestments site and they sent me a weird hammer.

[SteyrAUG]

Where did you get the hammer from? I got one from that Cddninvestments site and they sent me a weird hammer.


Got it from CDNN, worked just fine. It was identical to the one I replaced. I've got a spare if you are interested. Can post pics side by side with the bobbed hammer I removed.