M16A1 Assault Rifle, 5.56x45mm

FactionsUnited States Army
United States Marine Corps
Australian and New Zealand Army Corps
Weapon Type Assault Rifle, Magazine-fed
Roles Grunt (US Army, USMC)
Pointman (ANZAC)
Radioman (US Army, USMC)
Commander (ANZAC)
Inventory Slot Primary (Slot 1)
Variants N/A
Caliber 5.56x45mm NATO

“Introduced into wide service in 1968, Colt's M16 design became the standard in modern assault rifles”
— in-game description

The M16 family of rifles is often the standard-issue service rifle to United States soldiers, as well as many of its allies, ever since the Vietnam War. The variant used by South Vietnamese forces in Rising Storm 2: Vietnam is the M16A1, which is a select-fire, gas-operated rotating-bolt assault rifle chambered in 5.56 x 45 mm NATO, fed via 20-round detachable box magazines.
However, since the M16A1 often faced reliability issues in relation to the feed system, soldiers frequently avoided loading the full 20 rounds into their magazines. To simulate this, M16A1 magazines in-game only contain 18 rounds.


Developed as part of the US military's search for a firearm chambered in a cartridge ideally balanced between the hefty and unwieldy .30-06 and the lightweight but under-powered .30 Carbine, the M16 is the cutting-edge result of two decades of engineering and development.

In its initial stages, the attempt to consolidate the US military's arsenal after WW2 and come up with an elegant solution to fill the gap for a select-fire battle rifle saw the adoption of the M14, the successor to the M1 Garand. However, early reports from the Vietnam War suggested that the M14 was woefully outclassed by the AK-47, which had far better control in fully automatic fire, in turn translating to fire superiority over the Americans. The only other alternative select-fire weapon the Americans had was the updated M2 Carbine, but it was soon discovered that .30 Carbine was limited in versatility and under-powered.

Originally in 1956, to meet the military's requirements, ArmaLite had submitted the AR-10 prototype - a futuristic-looking aluminium and composite lightweight rifle chambered in the new 7.62x51mm NATO round. The military had adopted the M14 by this stage, but they were forced to consider a request for a 5.56 cartridge and rifle just a year later in 1957. This was ArmaLite's AR-15 - the precursor to the M16.

Following this, there was much controversy over the split between the M14 and the AR-15: whereas the latter was enthusiastically received by early Special Forces units trialing the weapons in Vietnam, many, including the Army, were reluctant to adopt two separate weapon platforms, insisting that the M14 was sufficient. Finally, the M14 gave way to the overwhelming evidence of effectiveness and the M16 was formally adopted for jungle warfare operations in 1964. Unfortunately, the early reputation of the M16 was quickly tarnished due to its poor reliability record in the harsh conditions of Vietnam. Because of its direct-impingement gas system, residue from fired ammunition would be returned to the receiver, causing a build up that negatively affected the weapon's performance. This caused the infamous 'failure to extract' (where fired cartridges remain lodged in the chamber) which unfortunately translated to significant casualties in combat, otherwise easily prevented. It was later found that a large part contributing to the malfunctions was the simple lack of cleaning (troops were instructed that the new rifle somehow was capable of cleaning itself and hence were not issued kits nor taught how to clean). Other factors critically included the powder of the cartridge, which left a lot more residue, as well as the inexplicable decision to remove the chrome plating for the bore which would have helped prevent corrosion, that the AR-15 had so strongly boasted.

As a result of this, the M16A1 formally replaced the original M16 in 1967 and emphatically removed next to all issues pertaining to reliability. New features also included a forward-assist mechanism and a chrome-plated bore. Gradually, confidence was regained and the M16A1 became widely accepted. The M16A1 replaced the M14 as the US military's standard-issue rifle in 1969.

Weapon Specifications


The 20-round M16A1

Rifle, Caliber 5.56 mm, M16.

Ammo Type 55gr M139 FMJ
Rounds Per Magazine 18+1 Rounds
Magazines 8 Magazines
Weight Per Magazine 0.34 kg / 0.74 lbs
Weight 2.89 kg / 6.37 lbs
Features Attachable Bayonet
Firemodes Fully Automatic
Rate of Fire 750 RPM
Recoil Vertical: 175
Horizontal: 40
Spread (MOA) 1.5
Length 1000 mm
Melee Reach 1560 mm
Instant-hit Damage 95
Damage Value 396
Energy Impulse 176
Penetration Depth 10
Ballistic Coefficient0.12
Velocity 990 m/s


 E3 2015 trailer A US soldier carrying a M16A1 with an extended 30-round magazine.

  • The M16A1 was originally supposed to come with both 20-round and 30-round box magazine variants. The extended 30-round magazine was removed from the game shortly after the Closed Beta began, since 30-round magazines were historically not available until later in the war (circa 1971).
  • Despite this, 30-rounders is still found within the game SDK as well as seen on early promotional material, such as the E3 2015 Announcement Trailer.