With all my M77's (6 of 'em) and all my customer's, I clean the threads, put a little Locktite blue or clear fingernail polish on the threads, run 'em all in finger tight, grab the barrel and bump the buttstock on the floor to make sure everything is seated to the rear (I know, I know, the angled front screw is supposed to do that, but I do it anyway. Kinda anal, but the routine works for me.), and then I go gorilla or German tight on the front, tight on the back, and about an 1/8 or quarter turn snug on the middle screw. Mine all seem to love that setup.
