The Anti-Material Rifle (AMR) rifle is a burgeoning one with many different flavors available to suit customer requirements. In the late 1990s, ArmaLite undertook development of a new .50 caliber system all their own as the "AR-50". The weapon relies on a manually-actuated, bolt-action system firing either the .50 BMG or .416 Barrett cartridge. It has been in production since 1999.
Weighing in at 34lb, the AR-50 sports many of the features commonly associated with guns of this caliber: long, heavy-duty barrel assembly, an over-receiver optics fit, and a forend bipod assembly. Overall length is 59.5 inches. The exterior design is smooth with many fine lines running horizontally. The bolt lever is set over the right side of the weapon, favoring right-handing shooters. The trigger unit sits under the receiver in the traditional way. The skeletal shoulder stock helps reduce recoil and features such creature comforts as a buttpad and cheekpiece. At the business end of the barrel is a large, multi-baffled brake which also aids in recoil. Internally, the barrel has 1:15 right-handed rifling and is octagonal in shape. A monopod is fitted under the shoulder stock as an additional support point. The optics fit is installed over the receiver in the usual way though the Picatinny rail system lets the user customize the optics fit.
Under the AR-50 product name are three major variants of the base design: the AR-50A1B is the standard offering (an upgrade from the original AR-50A1) and chambered for .50 BMG. The AR-50-A1BNM is chambered for match grade ammunition in .50 BMG. AR-50-A1B-416 is chambered for the aforementioned .416 Barrett cartridge. The AR.30 is a dimensionally smaller version of the AR-50 and appropriately chambered for smaller caliber rifle cartridges such as .308 Winchester and .338 Lapua Magnum.
The .416 serves as an alternative to the .50 BMG and was introduced in 2005 following a request by the U.S. Naval Surface Warfare Center Crane Division. It is decidedly shorter than its BMG cousin.
The AR-50 is in circulation in the United States and Malaysia. In the latter, it serves PASKAL special forces elements.