I found there is a distinct difference in lower parts kits. Price is no indicator as some of the worst I have used were not cheap and some of the cheaper ones the best. With a Wyoming stone, JP springs and a adjusting screw thru the pistol grip bolt I can get a smooth, no take up, no creep 3 1/2 #s every time. I never use the pistol grip or trigger guard that come in the kits.