Tuning "As-Issued" M-1 Garands for competition is a process best compared to tuning a violin. The rules are basically that you must use mil-spec dimension parts, that for the most part none of the components can be National Match (NM) parts and you are limited to carefully fitting those parts. Ultimately that means managing the stack up tolerances of the pieces of the jig saw puzzle.
My 1980's issued DCM M-1 Garand is a good rifle. In 2005, I spent quite a bit of time tuning it. Subtle details. The rear sight aperture was not perfectly centered and it caused my rapid groups to meander as I chased the shadow of the peep hole. I swapped one that had a nice round hole in the middle of the nub and the groups responded accordingly. I also worked over the gas cylinder raceway, the lower band pin and adjusted the front handguard position so there's zero fore and aft movement. The result was a gun that reliably shoots into the 10-ring. That was enough for 2nd place at this year's CMP Western Games.
The pursuit continues. Another round of carefully fitted parts is in order. I got a CMP M-1 Garand stock kit to see if it would be a tighter fit for the gun. I also got some new metal parts for it. I put a new stock ferrule on the nose of the CMP stock and swapped it with the lower stock on the M-1. Looks like good things. The assembly is a close fit. I can feel the action touching the wood without undue pressure all the way around as it seats. The fit between the stock ferrule and the lower band is remarkably improved and the side-to-side play in the upper forearm is almost gone. Overall the swap looks to have eliminated up to 90% of the play that was in the old DCM lower stock. I've elected to stop here and not touch all the careful fitting work I did on the upper half of the gun so it will keep the upper wood furniture. This is about function not cosmetics and I do not fancy taking the gas cylinder off. That would put all the work I did to the upper half back to square one. No way unless there's a demonstrated compelling need.
Hopefully this change will tighten the groups and the tantalizing tease of my shots orbiting just outside the X-ring will come in enough to start increasing the X-count in my groups. We'll see. It takes a year of shooting and observing to really tell if this did any good or if I'm just having another jolly in the garage.