USP9 LEM light strike

[duc748bip]

I had a ver. 1 USP 9 converted to LEM.
First range trip went great with Magtech 115gr.
But last week with some LAX reload at least 2~3 out of a 10rd mag had light strike.
I don't know if I should call it "light strike" primer looks to have a firing pin indent right in the middle, but the edge look to be flattened against the slide. So it looks like primer has detonated, but maybe the flash hold has blocked?
XD 9mm and a Glock with Glockwork trigger and firing pin has no problem.

So my first course of action is try Magtech again.. Didn't work, still getting failure.
Second I'm going to put the ver.1 hammer spring back.
Third convert back to Ver.1 and have my reliable UPS9 back.

[starsnuffer]

If you changed the hammer spring without changing the trigger return spring, this will happen. Also, did you try both the light and heavy hammer springs from the LEM kit? I'd expect you to get light strikes if you left the original hammer spring, but it looks like you changed it.

Also, there is a known issue with the hole being drilled incorrectly on the LEM hammer. Make sure it's striking the middle of the firing pin, and that it is not canted to one side. If it is, call HK, they'll send you a replacement ASAP.

-W

[eville]

What do you use for cleaner?
Make sure you oil per the following:

http://stevespages.com/pdf/hk_usp_field_stripping_&_armorers_maintenence_manual.pdf