A few days ago, I got back from the range and decided the bad trigger pull on my USP9 had to go.

I knew HK makes a drop in match trigger kit for the USP, so I ordered a kit from RTG Parts (recommended on HKPro). www.robertrtg.com/misc.html
Cost delivered was $133.90.
It included a trigger with over travel stop, an allen wrench, a hammer, a mainspring, trigger return spring, and a flat sheet metal spring.
I followed the instructions here for disassembling the frame. www.brandywineits.net/hk/
Installation was quite easy. I got to work as soon as I got home from having my wisdom teeth pulled this afternoon. I got the job done half sedated, with a disassembled pistol in my lap and a bloody paper towel hanging out of my mouth. hereExternally, the pistol appears exactly the same, with the exception of the over travel stop in the trigger. Functionally, the trigger does not have the half cock notch anymore. I guess this means that decocking the hammer drops it against the firing pin, relying entirely on the firing pin stop to prevent an AD. I guess I should thumb the hammer down when decocking.
The trigger kit seems to have removed most of the ridiculous creep that the stock trigger had. The break is a lot cleaner than it was before. I think double action is a little lighter too. The overall trigger pull and reset is still long.
I may consider using a drop of blue loctite on the on the over travel screw. I'd hate to have it back out at a bad time.
I'd say it was money well spent to improve the one thing I hated about my USP. The real proof will be in the range report, which I'll hopefully post next week.

tag

hey cool site man

tag for later read

tagged like a mofo

neato!

Look at your new hammer.  Does it have a "D" notch cut in the front side of it?  If so, you are unfortunately not done with the trigger job.  The new hammers need to have a new hammer catch installed or as you noticed, the hammer will fall and hit the firing pin.  There is a post on HKPRO about a guy who was getting primer pecks from the firing pin when he decocked.  With the FP block, that should NOT happen, but it did.  His pistol is in need of a serious trip back to HK.  Go over to HKPRO and do a search on the Match trigger.  This has been in the last month or two but you need to make sure that if you have the new style hammer with the D shaped cut in it that you get the new hammer block also.  It is not included in the kit.

Well I just got back from the range. I ran a couple hundred rounds of wolf and adcom through it. The trigger seems to have broken a little and is a little lighter. I think it helped my mediocre shooting some, but I still suck.
I'll look into the new hammer block.

Edit: Here's the thread mentioned by Big-Bore

Edit 2: Just checked my hammer. It has the D notch and my old one doesn't. I guess I need the new hammer block.