As Dillinger said it is a good idea to check with calipers. Please check to be sure but "Your 6940 Colt" should have been manufactured since 2009 and should be the small Hammer and Trigger Pins .154 diameter. (Some call them .155) they are the same small trigger and hammer pin. Meaning the standard 2 Stage Rock River Trigger and Hammer unit should fit in with no problem at all. Just be sure to get the springs installed correctly. A lot of the Post Ban and later Colt AR-15s had the Larger .170 trigger and hammer pins. Please check but yours should have the small pins .154.