Announced on Nov.9 by the Department of Defense, Colt's Manufacturing Company and FN America have each been awarded a $88.6 million contract for the production of additional M4 and M4A1 carbines, these contracts being modifications to existing ones and expected to be completed by September 2020.
U.S. Marine Lance Cpl. Cameron Davidson, K Company, 3rd Bn, 3rd Marine Rgt, III Marine Expeditionary Force, with his M4A1 carbine at the Kaneohe Bay Range Training Facility, Marine Corps Base Hawaii, July 26, 2018. (Picture source: USMC/Sgt. Jesus Sepulveda Torres)
The M4 carbine is a shorter and lighter variant of the M16A2 assault rifle. The M4 is a 5.56×45mm NATO, air-cooled, direct impingement gas-operated, magazine-fed carbine. It has a 14.5 in (370 mm) barrel and a telescoping stock. The M4 is also capable of mounting the M203 and M320 grenade launchers. The distinctive step in its barrel is for mounting the M203 with the standard hardware. The M4 is capable of firing in semi-automatic and three-round burst modes (like the M16A2 and M16A4), while the M4A1 is capable of firing in semi-automatic and fully automatic modes (like the M16A1 and M16A3).
The M4 product improvement program (PIP) is the effort by the U.S. Army to modernize its inventory of M4 service rifles. Phase I consists of converting and replacing regular M4s with the M4A1 version. This variant of the rifle is fully automatic and has a heavier barrel, and is given ambidextrous fire controls. Phase II of the PIP explored developing a new bolt carrier. 11 designs were submitted. The competition was scheduled to conclude in summer 2013, but ended in April 2012. Over six months of testing revealed that the current bolt carrier assembly outperformed the competing designs, especially in the areas of reliability, durability, and high-temp and low-temp tests. Phase II also includes a competition for a free-floating forward rail assembly.
In March 2015, the Army launched a market survey to see what the small-arms industry could offer to further enhance the M4A1 to an "M4A1+" standard. Several upgrade options include an extended forward rail that will allow for a free-floated barrel for improved accuracy with a low-profile gas block that would do away with the traditional triangular fixed front sight, removable front and rear flip-up back-up iron sights, a coyote tan or "neutral color" rail for reduced visual detection, a more effective flash suppressor/muzzle brake, an improved charging handle, and a new single-stage trigger module. In June 2016, the M4A1+ was canceled after reviewing the offerings and determining that there were no major upgrades currently offered.
