The Accuracy International AWM rifle is a variant of the British Accuracy International Arctic Warfare (AW) rifle that was the basis of a family of sniper rifles using the Arctic Warfare name. As such the design details of the AWM variant are similar to the ones found in the basic AW rifle system. Compared to the AW, the AWM has a longer bolt to accommodate dimensionally larger magnum-length cartridges such as the .300 Winchester Magnum and the .338 Lapua Magnum. The bolt head, locking ring, and extractor and magazines were also revised to work with the increased size and operating pressures of magnum rifle cartridges.The AWM features a detachable single stack removable box magazine which holds five rounds. The normal cartridges for this rifle, and the ones which have been accepted by NATO for use in AWM rifles, are .300 Winchester Magnum and .338 Lapua Magnum.