I never heard so much crap about the M14/M1A that I've found on the internet.
I've been shooting them since 1966, got my M1A in '77 and been shooting it every since. Ran and Coached the Alaska National Guard for better then 10 years using M14s, shot competition with it for about 35 years.
Went to sniper school and taught sniper schools with the M21 (NM M14).
You can believe what you want, you can do what you want but I'll tell you what I've found out about the M14/M1A in the last 47 years.
It don't care whether it shoots 308 or 7.62
It don't care if you use (=/<) 180 grn bullets
It does like Medium burning powder, 4895, 4064 and similar.
It does not like slow burning powder stay away from 4350, 4831, and similar
It DOES NOT need to be shot at super velocities, that doesn't help accuracy, you want to shoot further, adjust your sights, not the powder charge. Keep all loads to below 2600 fps, the closer you can get to 2200 fps and still work the action is the most accurate in a 308/7.62.
Stay away from 168 and less, when shooting past 600 yards. Plenty of good bullets if you want to go to 1000. 155s are nice in bolt guns but you have to push them faster then the gas gun likes.
Even Standard Grade actions do not like to be taken out of the stock, no reason to, there is nothing on the M14/M1A that can't be cleaned and lubed while the action sets in the stock unless you're trying to impress some drill Sgt. THIS INCLUDES THE GAS CYLINDER AND PISTON.
After you shoot a few rounds out of the M14/M1A you'll see some shinny spots where you had metal to metal wear, THATS WHERE THE GREASE GOES.
I know when it comes to loading every gun is different and the loads have to be tailored to individual rifle. That's true, but if you have 24 M14s your loading for its not always possible. If thats the case, load 41.5 grs of 4895 in Winchester or LC Match Brass, Fed Match Primers and 168 or 175 SMKs.
That load works, I've seen more then one cleaned 1000 yard target out of different guns using that load.
NEVER, NEVER, use a jointed or coated cleaning rod on a M14/M1A or any other rifle that has to be cleaned from the muzzle. Use a one piece stainless steel rod and a rod guide. You can make one out of a shotgun hull by punching out the primer and drilling the primer pocket to take the cleaning rod. Just slip the hull over the flash hider.
Leave the flash hider as issued, if you want to, ream it us a #7 reamer. That keeps water drops from interfering with the path of the bullet, but KEEP the ORIGINAL Hider. When using 41-42 grns of 4895 at night, you wont be able to see the muzzle flash.
Stay away from adjustable gas plugs, the rifle doesn't need them.
Sorry for the rant, but I learned about M14/M1A before the internet told me how to shoot and care for them. My 1977 version of the M1A still shoots.
I know I forgot tons of info on this rifle, I'll probably remember them after I hit the sack.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071