The Masada rifle was developed by US-based company Magpul Industries,which became famous for its line of aftermarket accessories and replacement parts for firearms. Work on the new modular rifle, suitable for civilian, police and military applications and designed more or less along the lines of the SCAR program commenced in 2006. First prototypes were shown to the public in 2007 at ShotShow, and early in 2008 it was announced that new rifle (previously known as Masada) willbe mass produced by famous American gun-making company Bushmaster Firearms. Current plans are to introduce civilian and police(semi-automatic) versions in mid-2009, with military select-fire version scheduled for production in late 2009. It is also planned to introduce Masada / BushmasterACR rifles in 5.56mm / .223 Rem caliber; other calibers might followlater. Magpul also is developing a 7.62×51 / .308 Win version of the Masada / ACR rifle, provisionally known as Masoud. It is still in early development and no information is available on its date of release to the public.
The Masada/ BushmasterACR rifle is gas operated, semi-automatic or selective-fired (Military version only) weapon of modular design. It utilizes aluminum allo yupper receiver, with polymer pistol grip / trigger / magazine housing(lower receiver) unit which is attached to the upper receiver using cross-pins. Various types of lower receivers are planned to accommodate different types of magazines (i.e. Ar-15 type magazines as opposed to AK-type magazines). The trigger / manual safety unit is made as a single removable item, and it mostly utilizes Ar-15-compatible parts. The barrels of ACR / Masada are quick-detachable, with short-stroke gas pistons attached to each barrel. To remove the barrel(for change, inspection or maintenance), user has to remove polymer handguards, then swing down the wire lever, located below the barrel,turn the barrel to unlock and pull it forward and out of the receiver.All barrels are free-floated within handguards to achieve consistent accuracy. Bolt group also is made as a single unit, with captive return spring and rotary multi-lug bolt which locks directly to the barrel breech. The standard magazine housing, which is suited to accept Ar-15 type magazines, has ambidextrous magazine release buttons. The ambidextrous bolt stop release button is located at the front of the triggerguard. Safety lever is also ambidextrous, and charging handle can be installed on either side of the gun, depending on user preferences. Depending on the version (or user preferences) ACR /Masada rifle can be equipped with various Magpul-made buttstocks, fixedor side-folding, and adjustable for length of pull (some also with adjustable cheek rest). Each Masada/ BushmasterACR rifle gas integral Picatinny rail on the top of the receiver;additional accessory rails can be installed on forend according to user preferences. Masada / BushmasterACR rifle can be fitted with removable iron sights, and/or with any optical or night sight with appropriate mounting.