AR-15/M16: The Rifle That Was Never Supposed to Be

The forward assist bolt closure mechanism. The M16A1 (shown) had the “tear drop” style while the new M16A2 has a round button style.

The forward assist bolt closure mechanism. The M16A1 (shown) had the “tear drop” style while the new M16A2 has a round button style.

The “Shorty” Program Revisited: The M4 Carbine.

In 1994, the Army adopted the second carbine of the 20th century and the first general issue carbine since 1941, the M4, perhaps the finest carbine ever developed. They were, at first, to be used by special operation units, but then were selected for use in many other units. Deliveries began in August of 1994, from Colt’s Manufacturing, for 24,000 M4 carbines contracted at $11 million; another contract followed in 1995 for 16,217 M4A1 carbines.

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The M4 is basically an M16A2 with a telescoping butt stock and a 14.5-inch barrel. The barrel has the heavy profile of the M16A2 barrel with a modified groove to accommodate the M203 grenade launcher. With its 14.5-inch barrel, the M4 fires the M855 Ball round at 2900 fps.

The M4 incorporates the M16A2 fully adjustable rear sight. Colt’s Manufacturing claims there is little, if any, difference in accuracy at ranges up to 500-600 meters. M4 carbines can be found with either full-auto or burst settings. The M4 duplicates the reliability and accuracy of the full-size rifle and weighs only 5.65 pounds.

The M4 has two variants, the standard M4 and the M4A1. The M4A1 is identical to the M4 with the exception of its removable carrying handle, which is attached to a Picatinny Weaver rail system. This arrangement enables easy attachment of optical sighting systems or, by reattaching the carrying handle, use of the iron sights.

Rebirth of the AR-10, Further Developments by Gene Stoner

The legacy of the ArmaLite rifles is far from over. The great weapons designer, Eugene Stoner, never stopped working on his AR-10 design. He, along with C. Reed Knight of Knight’s Manufacturing, perfected the AR-10 and added many design features of the M16A2, to build the SR25 (Stoner Rifle Model 25). The model number comes from adding the 10 from the AR-10 and the 15 from the AR-15.
Basically the SR25 looks like an M16 on steroids, beefed up to accommodate the 30-caliber round. The SR25 Match rifle is a 7.62×51mm NATO sniper rifle. Knight’s Manufacturing is one of the only manufacturers that guarantee their rifle will shoot one minute of angle at 100 yards using factory 168-grain Match 7.62×51mm NATO/308 Winchester ammunition. This rifles incorporates the 5R rifling sniper barrel manufactured by Remington Arms for the M24 sniper rifle.

Knight’s Manufacturing is the only company to which Remington has ever sold these precision barrel blanks. The 5R rifling is designed to optimize the use of 168-grain Match 7.62×51mm NATO/308 Winchester ammunition. Many firearms experts claim the SR25 is the most accurate semi-automatic rifle in the world.

In May of 2000, the U.S. Navy SEALS adopted the SR25 — now classified as the Mk 11 Mod 0 — as a full weapons system: rifle, Leupold scope, back-up pop-up iron sights and a sound suppresser. This is a modified SR25 Match rifle, which has a 20-inch barrel instead of 24-inch barrel. Following this sale, the U.S. Army Rangers also purchased SR25 rifles.

Production Sources of Civilian/ Military Versions of the AR-15/M16

The AR-15 rifle has been copied all over the world, in military and sporting configurations. The Canadian military adopted the C7 as its main battle rifle. The C7, literally a modified M16A2 rifle, is manufactured by Diemaco of Ontario, Canada, an unknown company to most of the world but a large player in this weapons system.

4 thoughts on “AR-15/M16: The Rifle That Was Never Supposed to Be

  1. master gunny

    As the armorer for the 6th Engineer Bn I one had to use a hammer and screwdriver to force the bolt into full battery (with a round in the chamber!) in order to clear a malfunction. I was shocked because the weapons was not anywhere dirty enough to explain the severe malfunction. That same day I have another stoppage, same problem, but again the fowling was not that severe. I could go on and on with why I feel the weapon is a poor choice for an infantrymen but suffice to say that I will stick with my M1A and HK-91.

  2. master gunny

    With respects it’s obvious to me that you guys are too young to remember the controversy surrounding the introduction of the M-16. Not mentioned in yourt article were the constant complaints about the weapons, their unreliability, the congressional hearings on the malfunctions that that were literally getting our tropps killed in Vietnam. Numerous accounts of troops found dead in their fighting holes with their weapons diassembled were presented as evidence that the weapon was despised by the troops. Mothers would get urgent letters from their sons asking for cleaning gear and solvents because the weapons fouled so easily and severely. The forward assist, and chrome chamber were just a couple of the modifications necessary to solve some of the problems.

    More offensive to me was the remark that the M14 was prone to jams and problems and speaking from experience I can tell you that is exactly the opposite of the truth. The M14 was rock solid reliable, accurate, and robust. The M1-16 fragile, unreliable, ualofre

  3. tinock28

    I liked the article on the AR-15/M16 rifle very much, I remember an article back in 1956-57 in one of Gun Mag’s about the AR-10, I thougt at the time it was a good rifle.

    1. master gunny

      Read Colonel Moore’s book, “We were soldiers one and Young” to get a better understanding of how critical reliability is to a grunt. One passage, regarding Lt. Herricks surounded platoon, say it all. Troops fighting for their lives against overwhelming odds were forced to discard their weapons and pick up those of their wounded comrades in order to stay in the fight. Many times those weapons were also not functioning and so the troops had to rummage through the perimeter to find a working weapon. Trust me, that sucks