if it says 5.56 on th barrel it'll be fine especially being a colt you'd have the proper chamber. Either way my dpms likes the 62gr prvi 5.56 best. but im gonna start reloading soon so i'll work up a nicematch load for her. Hell even with winchester 5.56 white box stuff from academy i dont have any problems dinging the chest sized target at 300yds. this is with an eotech 512 no magnification at all. its a lot of fun shooting that distance. If i were you i would shoot the rifle some more and get to know it before you drop the money on a trigger job. Yea it'll be better either way but if i can do with a clunky stock trigger anyone can.