JBM - Personal - HK USP Trigger Smoothing - 7

Hammer

The bottom surfaces of the hammer contact the trigger bar when shooting double action. These surfaces need to be smooth. Make sure that you don't round off any of the edges. One of these edges contacts the sear, the other the trigger bar when shooting double action. Rounding them off will change the trigger pull for the worse and may make the pistol unreliable I smoothed the sides of the hammer, but I'm not sure it is necessary. If you do it, do not go too far up the side of the hammer or you will see the bare steel when it is assembled.

Drop the hammer into the frame and insert the hammer axle. Make sure that the hammer strut is in the slot on the bottom of the hammer. If you cannot pull the hammer back, it is probably misaligned. It should look like this when done: