This kit worked great on my M-66. Brought D/A to 7 1/2 lbs and S/A to 2.5lbs.
Tested with Rem 1 1/2 primers WW - WSP primers and Fed Primers. 250 round D/A with no fail to fires. Have not tested with CCI Primers yet. I'm very happy with the results, smooth as silk ! Ordering another kit for my M586. I have that gun set to the same specs but get some D/A fail to fires, I think the longer firing pin and lighter firing pin spring will give me the same reliability. The strain screw they supply is the cats meow. No grinding screw or using primer cup, just adjust then lock tight it.