Tinkered with the stock a little more today, still waiting for my park job to get back from Vulcan so I can install the front swivel. I sent them a bunch of stuff, including some laser etching, so it takes a while.
Here is another lesser known NM mod made to GI stocks (back before Sacks & Sons started making NM-specific stocks with thicker profiles, larger barrel routes and pre-milled for bedding). Basically, if you look at a USGI gas cylinder that was actually on a rifle for a while, you will see wear at the contact points for the stock band (i.e. the part you sometimes unitize to the cylinder), but you will also usually see wear on one side or other of the gas cylinder tail.
The M14 drawing only leaves about 1/64" (or less) between the gas cylinder and either side of the stock "nosecap" (aka ferrule). Ferrules are just thin stamped steel and the stocks themselves vary a little in size. Under recoil and barrel whip, the gas cylinder often touches the inside of the forestock and affects accuracy.
One of the NM mods is to grind out the ferrule and sand out the stock inletting to allow more clearance for the gas cylinder tail, preventing any contact between cylinder and stock during firing.
Many builders overlook this change.
There are two variants of stock ferrule, some are pressed on with large fingernail-like detents (like on my Winchester stock). Those ferrules are impossible to remove intact. Others are just punch-dimpled on the sides and can be removed to be ground out. If you remove the ferrule, you re-install it with epoxy to "bed" it in place. On the large detent stocks, I pry the forward lip up a little to create a small gap and flow viscous 2-part epoxy in that way, I then flow cyano-acrylate glue in from the back side joint between the ferrule and the stock inlet to secure it more solidly to the wood, and then grind everything together with a dremel sanding cylinder. They don't budge after that.
In this photo, I've not yet oiled the areas where I removed wood so you can see the contrast.
You check fit with a NON-unitized cylinder installed on a barrelled action without the stock band installed so you can visually check for clearance. If you don't have good clearance all the way around, then you remove a little material until you do. Obviously, you want to start with a stock that is not appreciably warped with a well-centered gas cylinder and barrel.
Hope that helps anyone looking to further accurize their M14s
In other news, I shot 20 rounds of hirtenberger through the rifle last week. Function was 100%. Rifle was doing around 3MOA prone unsupported. I'll get a better sense of what it can do when I get all the parts back and scope it on the bench. I've also installed a Sadlak airborne mount and will be dropping on a Busnell Elite 10x40 mildot, similar to how some of the M21's were set up. That should overcome my aging eyesight and give a better account of what the rifle can do with military ammo.
If I can;t get 2MOA with the Hirt, I'll bed the stock in bisonite.
