Most snipers and sharpshooters used an M-14 (if it was really accurate, and some are sub .5 MOA out of the box), but usually the heavy barrel M-21. Some of those later used a wood stock with a high buttlplate, like the FN-FAL, and a pistol grip.
The bolt actions mostly used the Redfield 3-9x40 sight, with the Accu-Trak range-finding reticle. Most of the M-21s used the Leatherwood 3-9x40 ART range-finding scope. But there were M-21s with Redfield scopes, and bolt action rifles with Leatherwood scopes. I still own one of these M-21s, and will take some photos of it up close. I have photos of the scoped M-14 and M-21s in action, and can post those. Some I need to scan.
The M-21 snipers usually worked in 2-man teams in the Army or Marine Corps. The second man, who was doing spotting with a high-power glass and binoculars, carried a bolt action rifle. A lighter rifle is better when carrying that other gear.
The M-21 barrel was stout enough to support the Sionics suppressor, supplied by CIA operator Mitch Werbel.
The M-14 could not shoot the high pressure (65,000 PSI) M-60 ammunition which was most accurate and had the greatest reach, which is another reason for the bolt-action rifles. (See my previous post on the history of the 172/173/175 grain ammunition for both the .30-06 and .308 Winchester).
I still have some of the white box 7.62x51mm NATO ammunition, as well as the machine gun ammunition issued to snipers. Will snap some photos of that stuff, too, and probably put it in the ammunition thread.
