Arms Material was a brand or series of firearms produced during the 1970s and 1980s. The main output was a series of rifles and carbines used by Big Boss's mercenary forces and within certain areas of the U.S. military.
List of firearms
AM MRS-4 Rifle
Officially the Arms Material Multi-purpose Rifle System model 4. Designed for infiltration missions, the AM MRS-4 is a variant of the FN FNC (seen in previous MGS games) equipped with a shortened barrel, an optional mounted flashlight, and a suppressor. Its suppressor is light, adding minimal weight but sacrificing durability. The shorter barrel allows for ease-of-handling, but decreases the weapon's effective range. Post-Peace Walker incident, it was used alongside the M16A1 as one of the standard assault rifles of the Militaires Sans Frontières. Due to its relatively low rate of fire and limited (usable) suppressor lifespan, this rifle was used more often during covert operations where minimal gunfire was expected.
AM MRS-4 Rifle (SL) [w/Mark-Erasing Flashlight]
[AM Multi-purpose Rifle System model 4 (Special Light.)] Same basic properties as a standard carbine, but this model features a flash light with a unique function that erases markings when shined on.
AM MRS-4 Rifle M3
[AM Multi-purpose Rifle System model 4 Mod 3.] A customized version of the standard carbine, equipped with a red dot sight, a magnification device, and an under-barrel grenade launcher attachment. Used by Big Boss and the Diamond Dogs during the 1980s.
AM Rifle Type 69
[Arms Material Rifle Type 69.] The main service rifle of the U.S. Marine Corps personnel stationed at Camp Omega. It is, or resembles an AR-18 variant crossed with M16-style furniture and is chambered for 5.56x45mm rounds. Its longer barrel is well-suited to the combustion properties of its ammunition, giving it an effective range greater than that of the carbine model. However, it can also make the weapon harder to handle in tight spaces.
AM-69 AAS Rifle
[Arms Material Type 69 Advance Assault/Support Rifle.] A custom assault support model of the Type 69 assault rifle, equipped with a under-barrel grenade launcher and three-step variable-magnification scope.
AM D114 Pistol
[Arms Material Delta-114 Combat Pistol.] A standard-issue Marine Corps large-caliber pistol. At close range, its destructive power rival that of a rifle, with the stopping power to match. It seems to resemble a 3-way hybrid of the Browning Hi-Power, the Colt M1911A1, and the CZ-97.
Behind the scenes
Most Arms Material firearms resemble those made by Fabrique Nationale Herstal (with the exception of the AM 114D pistol). The weapons they are based off of are mentioned above.
Getting the Premium Package/Collector's Edition for The Phantom Pain will net the player with a DLC package for the third iteration of Metal Gear Online, which includes a gold version of the AM MRS-4 weapon, which is unlocked after the player reaches level 4. More accurately, it was a gold skin option for the AM MRS-4 rifle itself.