I tried to convert my V2 LEM USPc40 to light LEM. Everything went in well. Except for a really gritty, hanging trigger return. Decided to change over my 45c, USP45C, and my 2000sk. All went well with trigger return on all of the being smooth with a good trigger return. Sooooo, I tore the USPc40 down again and went on to clean everything. Well, I found a crack at the hammer end of the trigger bar. After looking really close, I could see that the trigger bar, because of the crack, was not straight. Thus, the trigger bar was rubbing on the side of the of the frame. With the heavy LEM trigger return spring, no real problem. But it did show up with the light LEM TRS installed. I ordered a new trigger bar from HKparts. All should be good in a few days.