Sweet Sixteen

Thanks to NirvashTec for helping me source vital material and documents that helped with the build.

Summary

The M16 Rifle, formally Rifle, caliber 5.56mm, M16, is an American assault rifle designed by Eugene Stoner, Jim Sullivan, and Bob Fremont at Armalite, and manufactured by Colt's Manufacturing Company, among others. A direct descendant of Stoner's earlier work with the AR-10, it was Jim Sullivan and Bob Fremont who scaled the AR-10 down to the AR-15.

A weapon controversial for its technical qualities, ballistic performance, and initial procurement decisions, it soon matured into an accurate, powerful, and reliable weapon. The extensive use of computer-controlled machining, aircraft-grade aluminum, and the use of a small-caliber, high velocity cartridge was nothing short of revolutionary.

The longevity of the M16 can be attributed to its simple and sophisticated design which gives it legendary accuracy, lethality, and adaptability while keeping it reliable, rugged, easy to use, and easy to maintain.

History

Formally adopted by the US Air Force in 1964, it and its derivatives have remained the standard service rifle of the US military. 8 million M16s have been made, with 90% still in use.

Based on the AR-10 by Eugene Stoner, it was redesigned by Jim Sullivan and Bob Fremont to accept the .223 Remington cartridge. The initial success of the weapon was marred by its disastrous initial fielding in Vietnam. However, fixes came fast, and within a year it was the GI’s delight it should have been from the beginning.

Today, the M16 itself is largely supplanted by shorter weapons. Most popular of these shortened weapons is the M4 carbine, itself a shortened M16. Many have tried to replace it, though success in doing so is uncommon.

Upgrades: Enhancing Excellence

The M16 assault rifle would see iterative development over its lifespan, both to accommodate for the desires of various services as well as to exploit new developments in optics mounting.

The original M16 and M16A1 were relatively light and handy weapons, about 3.4 kg or 7.5 lbs loaded, the only difference between the two was the M16A1 had the forward assist.

The M16A2 introduced a heavier barrel outside the handguards which can use the 5.56mm NATO round accurately, a new adjustable sight, stronger receiver, a slightly longer stock made of Zytel, and the 3-round burst limiter. The M16A3 is identical except it is full auto capable.

The M16A4 introduced the flat-top upper receiver with rails, making the mounting of scopes much easier. KAC railed handguards were made standard,

Derivatives: Alternative Arrangements

The M16 assault rifle would form the basis for many designs, either by Colt, made under license, or unlicensed copies. These designs would in turn be the basis for further development. Due to the sheer number of derivatives, this will only cover the major derivatives in military use worldwide.

CAR-15, Commando, and the M4: Baby Armalite

As soon as Colt acquired the rights to the AR-15 design, they began development of several variants for military use, including shortened weapons. The resulting CAR-15 carbines were incredibly popular, and would evolve into the even more successful M4 Carbine. Further information can be found on my M4 Carbine build.

These shortened weapons found favor with police, military, and special operations customers. The M4 in particular had replaced the M16 as the primary service rifle of the US Armed Forces.

Colt 9mm SMG: The M16 goes 9mm

The Colt 9mm SMG is essentially the CAR-15 modified to use 9mm Parabellum. While the Colt 9mm SMG is externally quite similar and duplicates all the controls, the Colt 9mm SMG operates quite differently. Rather than Stoner's expanding gas system, the Colt 9mm SMG relies on direct blowback.

The Colt 9mm SMG saw more limited success due to limited production and Colt’s marketing; they knew that the Colt 9mm was a direct competitor to compact carbines, including their own Colt Commando, and that it would be unwise to market products that cannibalize each other's sales. It was also anticipated that the Colt Commando would be a more attractive option for those looking for close-range firepower.

M231 Firing Port Weapon: Bradley’s Bullet Hose

The M231 Firing Port Weapon was a heavily modified M16 rifle designed specifically for the firing ports of what would become the M2 Bradley IFV. While the prototypes were fitted with flip-up sights and a wire collapsible stock, the production weapons would have no sights or stock; the weapon was screwed into a firing port and aimed by “walking in” the tracers via vision blocks.

The internals of the FPW are very different; it fired from an open bolt, could only fire full auto, and had a completely new bolt carrier, buffer, buffer tube, trigger group, and recoil spring. Without any sights or stock, and a cyclic rate of 1100 rpm, it was mainly intended for suppressive fire.

The weapon is still in service, although armor upgrades to the M2 Bradley blocked off the side ports, leaving only two firing ports in the troop ramp. The weapon saw limited service in the 2003 Iraq War as means for Humvee and MRAP gunners to fend off enemy combatants too close to bring the turret-mounted weapons to bear.

Mk 12 SPR: 75 in 77

As early as 1965, sniper variants of the M16 were developed. However, it would not be until the late 1990’s did sniper variants of the M16 begin to enter service.

The Mk 12 SPR, or Special Purpose Rifle, was developed by NSWC Crane Division, who supports the maintenance and development for weapons intended for use by US Navy SEALS and also for weapons intended for other US Special Operations.

The Mk 12 SPR was designed as a way to provide a weapon in a weight, size, and performance capability between sniper rifles such as the SR-25, and the M4 Carbine. To achieve this, the weapon was given a heavier free-floated barrel, an OPSINC silencer, and new precision ammunition was developed.

The combination of the Mk 12 SPR’s accurization, match-grade ammunition, and highly-trained snipers is a deadly blend; in one mission a pair of unnamed US Special Operations snipers with the Mk 12 in Afghanistan scored 75 kills with 77 shots.

Diemaco C7 and C8: The Black Rifle of the Great White North

The Diemaco C7 and C8 are license-built derivatives of the Colt M16 and the CAR-15, respectively. Under the Small Arms Replacement Program in the 1980’s, they replaced the FN FAL and Sterling SMG. While they are mostly identical to the Colt weapons, they feature many changes, such as cold hammer-forged barrels and the use of the M16A1 sights.

The C7 and C8 would be updated extensively, with the C7A1 featuring a flat-top receiver similar to the M16A4, though predating it. The C7A2 adds the stock from the C8 Carbine, a clamp-on rail, and green plastic. The C8 carbine, similar to the CAR-15, would evolve into the C8 SFW, designed by the British SAS and the basis for the new C8A3.

The C7 and C8 in all its forms have found significant favor with a variety of units outside of Canada, to include British special forces and Royal Marines, Norwegian special operations and police units, the Dutch and Danish Armed Forces, and Botswana.

Norinco CQ: Chinese Colt

The Norinco CQ is an unlicensed copy of the M16A1, manufactured by the China Ordnance Industries Group Corporation Limited, or Norinco. It is believed that they were reverse-engineered from M16A1 assault rifles acquired during the Vietnam War.

The CQ can be distinguished from the M16A1 in the use of round handguards of a different design to the Colt, unique shape to the stock, and a revolver-style pistol grip. In addition, the receiver is made from 6061-T6 aluminum alloy. While this alloy is weaker and less durable, it is cheaper and easier to work with, able to be injection-molded.

Several variants have been developed, to include a semi-automatic only variant for commercial sales on the civilian market, and a clone of the M4 carbine known as the CQ-A.

Introduced in 1980, the CQ is primarily intended for export, though some Chinese special counter-terror units use the CQ-A. As an export product, it has been successful, with known users including Cambodia, Iran, Sudan, Paraguay, and North Korea. It is known that the Defense Industries Organization of Iran manufactures an unlicensed copy of the CQ, known as the Sayyad, and that the Military Industry Corporation of Sudan manufactures a licensed copy of the CQ as the TERAB.

Technical Description

The M16 is a gas-operated, multi-lug rotating bolt, magazine-fed select-fire rifle. In the original AR-15 and the subsequent M16 guise, it is a true assault rifle. All variants have a cyclic rate between 750-900 rpm.

The M16 and M16A1 weighed 6.37lbs (2.89kg) unloaded and 7.5lbs (3.40kg) loaded with 30-round magazines, and was 39.00” (990.6mm) long. By the standards of the time, was a light and handy weapon, and its favorable characteristics still hold up to today’s shooters. With the M193 cartridge, it has an effective range out to 460 meters, well within the distances combat is expected to take place in. They cannot use the newer M855 ammunition, as while it will run reliably, the barrels don’t spin the bullets fast enough to stabilize them, and will not shoot accurately.

The M16A2, A3, and A4 weigh 7.5lbs (3.40kg) unloaded, and a whopping 8.79lbs (4.0kg) with a sling and loaded 30-round magazine, and are 39.62” (1006mm). While somewhat heavier, the improvements gave it somewhat better shooting characteristics in exchange for weight and handling. The M855 cartridge and its heavier bullets allow it to engage targets at up to 550 meters, though the range dial indicates an optimistic 800 meter effective range. The newer rifles can use the old M193 ammunition if need be.

Due to the popularity of the AR-15 system with militaries and gun enthusiasts, virtually every component is available from dozens of companies, and of varying quality.

This Rifle’s Lore: Right Arm of the IDA

This rifle belongs to the Paternian Republic, a powerful nation and founding member of the Intercontinental Defense Alliance. A regional power with global reach as well as less than friendly neighbors, it maintains a large military as a result. Said military gets into a lot of fights as a result. Said large military, in part due to the M16, tends to win those fights.

It would see use with the Paternian Army since 1963, though would be until 1978 that it was made standard issue. Seeing many upgrades, conversions, and developments over a century of service, it gave the Paternian Army infantryman considerable firepower.

The Paternian M16 would eventually blend features from the M16A1 and M16A2, much like the C7 rifle. This weapon was made by the fictional Bandit Firearms Division in Hartford.

Virtually every other IDA member would at some point issue the M16 as standard issue, with most manufacturing them under license. This was the result of extensive testing by many powers, and a general agreement that the M16 was the best rifle out there. As a result, it became the right arm of the IDA.