ACR

By 21st Century combatant assault rifles are aiming towards the concept of adaptive, modular and compatible, adapting to different role, modularly changeable between different calibre munitions, and being compatible with different accessories/components. This concept was widely demonstrated by the AR-15 platform used by civilian firearm enthusiasts who outfitted their AR-15 rifles with various different made receivers and parts, AR-15 rifles are considered extremely modular and adaptable to a variety of different functions, uses, calibre, and firing performances. Designed by Magpul Industries, Remington Arms and Bushmaster Arms, the Adaptive Combat Rifle (ACR), previously known as Masada, was presented to the military with this concept in mind. Designed in 2006 and presented to US Army on an Industry Day in 2008, ACR demonstrated the current carbine technology and competed to replace the M4 Carbine from US military during the 2011 Individual Carbine competition. The military version of ACR is produced by Remington Arms, Remington ACR classifies as a gas operated, selective fire rifle, it makes use of the short-stroke gas-piston operation of Stoner's AR-18, able to achieve 650 to 700 rounds per minute of fire rate. Remington ACR chambers the standard 5.56×45mm NATO calibre, or .300 BLK and 6.8×43mm Remington SPC designed for US special forces usage, can be fed by Magpul's own 30-round capacity PMag or all M16 style magazines. Fire selector lever is located above the pistol grip like M16 rifles, it toggles between fully and semi automatic as well as functions as a safety. Charging handle is placed similar to FN's SCAR where it is a horizontal reciprocating curved piece located above the magazine well, the magazine release is just above the trigger. All the features of ACR can be moved to either side of the rifle making it fully ambidextrous, empty brass can only eject to the right, but a deflector is installed to deflect spent brass away from left handed user's face. ACR is advertised to be adaptive, meaning the rifle can be quickly disassembled, parts can be replaced ands swapped quickly on the field without tools. To switch between firing calibres user simly has to replace the bolt head, barrel and put in a different magazine. Having access to different length barrels and foldable/extendable stock, ACR can quickly change into a carbine, PDW and DMR variant from the standard assault rifle configuration. Other features include various polymer made gun components to cut down weight, and a monolithic Picatinny rail along the top of the rifle to mount accessories. Additional Picatinny rails can also be installed on Remington ACR's handguard for the mounting of other compatible items. The Individual Carbine competition prematurely cancelled with no winner chosen, ACR did not win despite demonstrating all of its selling points, and the rifle itself did not enter mass production. However in 2008 Bushmaster International entered into a licensing agreement with Magpul whereby they would take over production, future development, and sales of the ACR, a semi-automatic version known as the Bushmaster ACR is released and supplied to civilian gun enthusiasts who are willing to purchase the ACR platform. Bushmaster also produced various aftermarket conversion kits allowing Bushmaster ACR to chamber calibres such as 6.5mm Grendel and 7.62×39mm Soviet.