Re: S&A M1A Supermatch cleaning?
No need to remove from the stock to clean.
However, the "occasional removal won't do any harm, and the rifle will return to zero.
One method of cleaning;
The obvious, remove mag, verify chamber clear and unloaded.
Lock bolt rearward, tilt rifle muzzle up, then muzzle down. You should hear the gas piston moving. If it's free, no cleaning required as yet and therefore no reason to remove the action from the stock.
Barrel cleaning gets done from the muzzle unless you employ something like the Otis flexible rod system.
Get a brass crown protector, looks like a funnel of sorts and inserts into the flash suppressor to guid /center the cleaning rod in the bore. Place the rifle in a cleaning cradle, muzzle higher than chamber, and rifle up side down. I pack a paper towel into the mag well to prevent solvent and oil spatter from contanimating the bedding.
Use grease ( not spelled o-i-l ) on the bolt roller and lugs.
Other than that, clean as normal, then go get it dirty again. repaet.