USP V1-2 Detent vs HK45

[Thoth0Amon]

Hey, new user here.

My new USP Expert in 9 functioned flawless over about 200 rounds, then the decocking action would occasionally seize up and require more than normal force to decock, or several slide racks to get it moving. It feels a bit rough, like there's a burr or something binding on the detent plate or the tensioning piece underneath. It's also got a more audible "click" once it decocks, the opposite of a smooth sounding click, too.

I've done the usual actions - checking for burrs, debri, detail stripping, oiling, the whole 9 yards - no luck. Still very stiff and occasionally seized up.

Meanwhile, my HK45 & it's detent works flawlessly.

So I had an idea - I switched out the V1/2 plate on the HK45 to the USP Expert, and viola - it works smooth and flawless, just like the HK45.

The plates seem to have a slightly different geometry / cut to them, but otherwise it works perfectly fine - way smoother.

So, question to the community - Should I just stick a HK45 plate in the Expert? Continue trouble shooting the original plate? Anything else I can check?

 

[Guyanaman1963]

Welcome to the site!
Have you called HK Customer Service? HK have a lifetime warranty.
M.

 

[AGG]

Welcome to the site.
Thanks for the report--- glad that you got it functioning the way that you want.

Tony

 

[Thoth0Amon]

Welcome to the site!
Have you called HK Customer Service? HK have a lifetime warranty.
M.

I'll give them a call - at least the HK45 plate seems to work perfectly, so that's a plus - more so just confused at this point as I can't find any reason for the original USP plate to be binding up on decock like this. Maybe some burr or imperfection I can't quite see.

 

[marquesgriffin]

Interesting troubleshooting—sounds like you already did more than most would. The fact that the Heckler & Koch HK45 plate runs smoothly in your Heckler & Koch USP Expert points pretty strongly to a tolerance or machining issue with the original detent plate. I’d be cautious about making it permanent, though, since geometry differences could affect long-term wear or safety. Might be worth contacting HK or just replacing the factory plate altogether.