To offer consumers a purpose-built precision rifle similar to the Designated Marksman Rifles used by today's military, DS Arms teamed up with Knight's Armament to put together a solid, heavy-barrel build. The result was the DS Arms ZM4 Service Series A4 Rifle. The heart of the DS Arms ZM4 Service Series A4 Rifle is the barrel, which features an HBAR profile and a rifle-length gas system, all designed to provide reliability and accuracy for a perfect shot, every time. To guard against corrosion, the barrels and chambers of each rifle are chrome-lined. Chambered in 5.56 NATO Length: 36 inches Weight: 6.5 pounds Includes one 30-round magazine Knig Mfg: D.S. Arms