View Full Version : Need help to swap the HK USC FCG to UMP lower

12-11-2011, 1:57 PM
This is my first time I am not sure where to start . Could any member walk me though .
Thanks in advance!

12-11-2011, 2:04 PM
lots of how to videos on this. I googled your subject and found this.


12-11-2011, 2:19 PM
He didn't have one that show how install the USC FCG to the UMP lower .

12-11-2011, 6:14 PM
Remove the auto-trip lever by pushing out that pin first. Take the lever and spring out and reinsert the pin. Punch and a small hammer to get it started.

Then make sure the UMP lugs will fit on the USC upper pins.

The trigger group pins should push out the same as the auto-trip lever pin did.