[hattriq27]

I converted my USPc to LEM last week and everything felt fine. Like the LEM trigger. I retained the stock hammer spring because I felt the long one was WAY to heavy a pull on the long stroke. I had read that you can keep your old spring to get a lighter pull. I took her to the range today and she was hitting the primers way too light. Only popping off 1 round every 2 or 3 tried.

I assume a firing pin spring is in order (this guy: HK Spring | HK FPBS - HKPARTS.NET) but I wanted some clarity first.

She's a KG date code if that matters

tyia for compensating for my lack of hk education

 

[hattriq27]

thanks for all of the input. She was a V3 before I switched, I left the old hammer spring in there because I liked the feel of the long pull better. I will swap in the spring that came with it and give it a whirl.

 

[hattriq27]

so I finally got around to taking her apart and took my time this time. I swapped the hammer spring with the short one with the kit and did the "pencil test". It launched it a few feet. I then switched out the new trigger i installed with the old one and that sucker sent the "pencil" about 6 feet. Me thinks the FP issue my be resolved. I note the long stroke is pretty heavy and the short stroke is very light. Have to run some drills to see if I am happy with her...well and that she fires properly ;-)

thanks for the help

 

[hattriq27]

toosixty

Miine was a V3 (DA/SA with decocker only, no safety), from the USP website

Variant 3: 
Double action/single action without "SAFE” position. Control lever (decocking lever) on left side of frame.

I now have the short spring from the LEM kit (which is black in color and as I understand is for the HK45c) and the original TRS that came with it in the pistol. The long spring (more silver in color) which is supposed to be the one for my pistol needed a 'roid raging beast to pull the trigger. Honestly, it wouldn't work with the long spring. The original hammer spring that was in my USPc is actually shorter than the HK45c version that came with the kit.

When I did the "pencil test" with the TRS from the LEM kit and my original hammer spring the pencil went maybe 12". No wonder it would hit the primers hard enough. I swapped to the long hammer spring from the kit and there was no way to successfully cycle the weapon. So I decided to swap the TRS to the original one and work through all of the spring again. With the original TRS the original hammer spring sent the pen a few feet, maybe 2 or 3. The HK45c sent the spring about 6 feet which is about the same for my Glock and Colt Series 80. The long hammer spring, forget it. 90lb full stroke pull.

 

[hattriq27]

I bought it used and I am still fairly new to HK (had a USPc and full in 40 but never modded them). I have no idea if any changes were made. I think I will hit the range today and try both the original hammer spring and the short hammer spring from the LEM kit to see how they perform.