Serial number Stock The M14 rifle was first furnished with a walnut stock, then with birch, and finally with a synthetic fiberglass stock due to the moisture in the humid jungle environments of rural Vietnam causing wood to swell. The stock was fitted with a hinged shoulder rest for improved user comfort when firing from a prone position. Original-equipment walnut and birch stocks carry the Department of Defense acceptance stamp or cartouche, consisting of an arc of three stars above a spread-winged eagle. After successful test firing, a proof stamp was also applied to these stocks consisting of a letter "P" within a circle. Rifles manufactured through late 1960 were provided with walnut handguards. Synthetic, slot-ventilated handguards were produced, but proved to be too fragile for military use. These were replaced by a solid synthetic handguard that is still in use, usually colored in dark brown, black, or a camouflage pattern. Rifling Standard M14 rifling has a right-hand 1:12-inch twist with 4 grooves. Accessories Although M14 rifle production ended in 1964, the limited standard status of the weapon resulted in the continued manufacture of accessories and spare parts into the late 1960s and beyond. M6 bayonet with M8A1 sheath M2 Bandoleer (has six pockets, each containing two 5-round Mauser-type clips for a total of 60 rounds, and a pouch for a magazine filler. The sling was adjustable and was held in place with a matte-black steel safety pin). Standard operating procedure was for the operator to use up the ammunition in the bandoleers before using the loaded magazines in the ammo pouches. The seam stitching of each pocket could be ripped out to allow the bandoleer to carry six loaded 20-round magazines. Sling: The service rifle used a one-piece cotton or nylon webbing sling, and the competition and sniping variants use the standard M1907 two-piece leather sling. Cleaning kit, contained in the stock's butt-trap, included a combination tool, ratchet chamber brush, plastic lubricant case, brass bore brush, four cleaning rod sections, cleaning rod case, and a cleaning rod patch-holding tip. M5 winter trigger and winter safety M12 blank firing attachment and M3 breech shield Cartridge charger clip (holds five cartridges) Magazine filler (or "spoon") for charging detached magazines externally: The M14 has a groove over the action that allows the operator to place a loaded clip and top off the attached magazine internally through the open action. M1956 Universal Small