Simple modifications can be made to increase the accuracy of any factory M1A- or M14-type rifle. In previous articles, we have covered gas system unitizing and handguard clearance. Another area we should address is clearance inside the forend of the stock for the gas system. When the rifle is fired, the barrel vibrates, and any contact between the gas cylinder and the stock aside from the lip of the front band is detrimental to accuracy.
Inspect the stock ferrule and make sure it is secure. If you can wiggle, it then remove it and degrease the inside surface and epoxy it in place on the stock. Devcon 5-minute epoxy works fine in this application.
Once the ferrule is solidly attached, we need to grind clearance into the wood and metal around the area where the gas system lives. Some armorers use files or rasps, but I’ve always found a Dremel rotary tool and a 1/2″ coarse sanding drum will quickly modify the ferrule and the area directly behind it.
A coarse half-round file is handy for removing wood further back toward the sling swivel attachment point. After modification, the exposed wood should be sealed against moisture. Study the photos for further clarification.