The USPc trigger will need to be driiled and tapped to fit the overtravel stop screw. I also read that some people dremeled the Match trigger to fit the USPc trigger guard. Or you can just install the match trigger kit without the trigger. The compacts already have the Match hammer spring. Just need to install the hammer, TRS, and nickel flat spring, assuming that your compact has the new-style catch + control latch + light FPBS.