Ditto from me...I've installed about 10 timneys in all kinds of rifles. They are easy, but, I screwed up on the MK-II...I filed too much. You'll need to completely install the trigger, springs and all, and then take the whole thing apart and file. Something about the tension w the springs installed makes a difference. I finally used the factory trigger with the timney sear and spring. Not as crisp as I'd like, but, 100% better then the trigger it came with. TAKE YOUR TIME AND GO EASY ON THE FILE!!!