The Theory of Evolution through Natural Selection: America's Black Rifle and Survival of the Fittest

By Will Dabbs, MD

In 1859, Charles Darwin published “On the Origin of the Species by Means of Natural Selection: Preservation of Favoured Races in the Struggle for Life.” Within its pages, Darwin proposed that creatures spontaneously improve in response to pressures from their environment. While the sci-entific, theological, and moral considerations of this tome play out in our culture even today, Darwin’s basic concepts find splendid application in the field of small arms.

Staatsbedrijf Artillerie Inrichtingen in the Netherlands produced some of the earliest AR-10 rifles. While these Dutch guns were sold in modest quantities around the world, many of them ended up in the hands of Portuguese Special Forces fighting in Africa. The Portuguese para-troopers who used these early AR-10 rifles in combat covered them in praise.

War Story, AR-10

Captain Ilio Capozzi was a former Italian Naval Special Forces officer who fought in the Dominican Republic through its several revolutions in the early 1960s. A mysterious fellow, Capozzi was rumored to have served with the German Gestapo in World War II. Enamored with the AR-10 based upon its limited use with Italian Naval commandos, Capozzi somehow acquired one of the few AR-10 rifles sold to Cuba immediately prior to its fall to communism.

As Capozzi fought alongside forces loyal to Dominican reformist leader Juan Bosch, his AR-10 rifle was his constant companion. Images of Captain Capozzi with his ArmaLite rifle are availa-ble in the Life Magazine archives from the period. On May 19, 1965, Capozzi led a brazen assault on the national palace in an effort at restoring constitutional rule to this battered country. Captain Capozzi died in this action clutching his prized AR-10.

Running the Portuguese AR-10

The Dutch-built Portuguese AR-10 is lighter than its contemporary competition, the FN FAL and G3. However, it is still more than 40 inches long. The in-line design aligns the recoil vector with the firer’s shoulder and helps minimize muzzle climb. The controls are all in the familiar spots.

The charging handle is a trigger-looking appendage that slides within the carrying handle and includes a sheet metal cover to help exclude battlefield funk. Magazines built for these early AR-10 rifles are pressed in a waffle pattern out of thin gauge aluminum and are intended to be disposable. This original 1960s AR-10 runs much like your modern full-sized AR-15 rifle only bigger.

Honey, I Shrunk Your Rifle

Robert Fremont, Jim Sullivan, Gene Stoner, and a few others at ArmaLite compressed the AR-10 down to accept the revolutionary .223 cartridge. The .223 launched a lightweight 55-grain bullet at blistering velocities. When combined with the space age design of the original ArmaLite AR-10 rifle this made for an unprecedented combat weapon.

In 1957, General Willard Wyman issued a request to industry for a small-caliber, high-velocity Infantry rifle. ArmaLite had fallen on hard times and sold the rights to the AR-10 and the smaller-caliber AR-15 to Colt in the late 1950s. Colt’s first military sale of the AR-15 was actually to Malaysia for 300 rifles in December of 1959.

After a well-publicized spot of controversy wherein substandard weapons were issued to American troops in Vietnam, the U.S. Army standardized the AR-15 into the M16A1 and eventually got most of its kinks removed. The product-improved version included a chrome-plated bore as well as a birdcage flash suppressor and forward assist device. While the M16’s early travails were attributable to a hasty design, inappropriate ammunition, and political intrigue all in comparable measure, the rifles used at the end of that wretched war were fairly dependable and effective. These weapons fed from pressed aluminum 20-round magazines.
Rumors abounded about the various attributes and liabilities of the M16 early in its adop-tion. One of the most prevalent was that the gun was built by the Mattel toy company. While this stemmed from the rifle’s revolutionary black plastic furniture, most of the guns used in Vietnam were manufactured by Colt.

War Story, M16A1

A friend who used an M16A1 in Vietnam related an anecdote wherein his motorized convoy was ambushed by a pair of Viet Cong occupying a fighting position constructed of stacked stone on some high ground overlooking a main supply route. After more than an hour spent firing ineffectively against the stone position with a ring-mounted M2 .50-caliber machinegun and a recoilless rifle, my buddy crept around behind the Viet Cong, catching them unawares. He emptied his 20-round magazine, downloaded to 18-rounds for better reliability, on fully automatic at a range of about 50-meters. In this case, the stone construction of the fighting position was the VC’s undoing. The little 55-grain high-velocity bullets bounced around the inside of the position and killed the two VC.

Taking the Mattel Rifle for a Test Drive

The M16A1 is indeed lithe and sleek. The smooth triangular handguards get mighty slick when they are wet, but they do a decent job of protecting your hands from the hot bits when the lead is flying thick and heavy. However, the teeth that define the cooling holes are remarkably fragile under hard use. The fact that the handguards are uniquely right and left components also immediately doubles the demands placed upon the Army supply system for replacements.

The thin profile barrel is fairly intolerant of protracted full auto fire, but sustained fire was never this rifle’s mission. Iron sights consist of an elevation adjustable round forward post as well as a flip-adjustable rear peep that can be zeroed using the nose of a cartridge or similar pointy tool. By the 1980s thirty-round magazines were plentiful, though the lack of no-tilt followers ensured that the magazine would typically be the weapon’s Achilles heel. As with all direct gas impingement weapons, the M16A1 does not suffer sloth when it comes to cleaning and maintenance.

The Miniaturization of the M16

In 1966, Colt engineers undertook a project to make the already-small M16 rifle even smaller. They cut the barrel back to 10-inches and topped it with a 4.25-inch moderator to im-prove performance and help attenuate the prodigious muzzle blast. They also developed a set of interchangeable round polymer handguards and a sliding buttstock. The resulting carbine was known by various nomenclatures depending upon the service. While XM177E2 and GAU5/A sufficed at times, the most common moniker was CAR-15. CAR stood for Colt Automatic Rifle, and it represented an early attempt at branding by Colt marketers wishing to identify their company rather than ArmaLite with the weapon.

War Story-CAR-15

In mid-1969, an OH-6A Loach observation helicopter on a Visual Reconnaissance mission overflew a Viet Cong machine gun position and was shot down. The crew chief escaped the wreckage with his M60. The pilot egressed with his CAR-15. Evading into a nearby rice paddy so as to make contact with an orbiting Cobra gunship, the two aviators went to ground.

Soon thereafter a group of six Viet Cong formed a skirmish line and advanced across the paddy, firing their AK47’s randomly. When the group got within 75 feet of the Americans, the pilot fired a single long burst from his CAR-15. Two of the six VC fell. The rest retreated into the jungle, subsequently laying down accurate fire from cover. Just as the Cobra expended the last of its ordnance and the situation grew dire, another half dozen Snakes arrived to thoroughly hose down the tree line. The two downed air crewmen were subsequently recovered unhurt.

The CAR-15 at Play

Running a Vietnam-era CAR-15 on the range will remind you of how incredibly light and maneuverable these rifles were before we started hanging so much junk on them. The weapon is sufficiently anorexic to make for easy portage even over long distances. The CAR-15’s iron sights are identical to those of the M16A1.

Recoil is a non-event, though these little rifles are indeed really loud. Halving the length of the barrel takes a terrible toll on the round’s velocity. As speed is the mechanism by which the 5.56mm is effective, this becomes a deal-breaker at modest ranges. However, for bad-breath applications like the jungle areas for which the gun was originally designed, little runs better.

The Family Tree Branches Vigorously

In the early 1960s, Eugene Stoner, L. James Sullivan, and Arthur Miller designed first the AR-16 in 7.62x51 then the AR-18 in 5.56x45mm. Where the AR-15 required fairly advanced manufacturing facilities to produce the aluminum forgings that became the upper and lower receivers, the AR-18 was designed for much simpler places. Taking a cue from the German StG-44, the AR-18 made maximum use of steel pressings in its structural components.

The AR-18 was a lightweight selective-fire assault rifle that fired the same 5.56x45mm ammunition as its AR-15 predecessor. However, whereas the AR-15 action consisted of little more than a piece of stainless steel hydraulic tubing that fed into the bolt carrier, the AR-18 sported a gas piston design that kept fouling out of the rifle’s action. The ongoing arguments regarding the relative merits of these two designs have spilled a sea of ink.

While commercial sales of the AR-18 were tepid, the gun did nonetheless go on to make a mighty splash. A slightly modified version of the AR-18 action drove the British SA80 bullpup and the German HK G36. Despite limited usage by the world’s militaries, the AR-18 was a popular illicit arm with the Irish Republican Army who cryptically called it “The Widowmaker.”

As the gun’s operating system was entirely contained within the forearm, the buttstock of the AR-18 was free to fold. The muzzle ended with a 3-pronged flash suppressor, and the reciprocating charging handle could be manhandled in the event of a stoppage. An M16 magazine could be converted for use in an AR-18 with a Dremel grinder in about five minutes. The line of recoil remained in alignment with the firer’s shoulder in the manner of the AR-15.

War Story, AR-18

The Cyberdyne Systems Model 101 Terminator tracked its quarry to a Southern California police station. After verifying with the duty officer that the girl was indeed in the building, the machine sized up the structure and rammed through the façade with his stolen vehicle. Emerging from the crumpled car with a Franchi SPAS12 shotgun in one hand and an AR-18 in the other, the Termi-nator proceeded to systematically move through the shattered building in search of his target, a 19-year-old girl named Sarah Conner.

There were thirty officers present at the time of the attack, and they resisted heroically with sidearms and AR-15’s. However, the Model 101 consisted of human flesh grown around a hy-per-alloy combat chassis all but impervious to gunfire. The cops did not have a chance.

In the mayhem that followed, Conner and Tech-Com Sergeant Kyle Reese, a soldier sent from the future to protect her, escaped in a liberated vehicle. The Terminator had removed the butt-stock from his AR-18, as his automated targeting suite did not require a weapon to be shouldered for accurate operation. As Conner and Reese sped away, he raised the AR-18 and emptied its 40-round magazine. The vehicle was moving too quickly for his microprocessor to establish a precise firing solution, so he riddled the car without hitting either occupant.Of course the preceding is pure fiction, but the movie “The Terminator” does include some cool full auto AR-18 action.

Running the Prodigal Son

Though it is difficult to capture in prose, the AR-18 feels a little bit snappier than the M16. For starters, the M16 produces a unique springy sound as the buffer cycles about a quarter inch from your face. The AR-18 lacks this twang. While the AR-15 is intrinsically the more accurate platform, the practical differences are trivial.

The bolt locks to the rear on the last round fired. Giving the charging handle a snatch disengages it to close on a fresh magazine. Sights are not unlike those of the M16, and the weight and balance are comparable to the older design. Magazine changes are about the same on both guns.

The AR-18 is markedly easier to maintain. AR-15 apologists litter the landscape with claims that the M16’s direct gas impingement system is comparably reliable to the AR-18 so long as the rifle is well maintained. That may be so but I have found that the AR-18 remains reliable pretty much whether you attentively maintain it or don’t.

Stoner’s Black Rifle Enters the Information Age

In the early 1980s, the Marine Corps drove a product improvement program for the M16A1 then growing a bit long in the tooth. The resulting M16A2 featured a heavier-profile barrel, round handguards adapted from those of the CAR-15, more user-friendly sights, and a handful of lesser features. The M16A2 also sported a 3-round burst limiter rather than the full auto capability of the A1.

In 1985, Colt began incorporating the best features of the M16A2 into the old CAR-15 now fifteen years out of production. In 1994 the resulting M4 Carbine was formally adopted for military service. This variant sported a 14.5-inch barrel that incorporated a barrel step machined to accept the M203 grenade launcher. The 14.5-inch tube was seen as a compromise between the inadequate 11.5-inch barrel of the CAR-15 and the bulky 20-inch version on the full-sized M16. The M4 sported the 3-round burst feature of the M16A2. The M4A1 was full auto. A buddy currently slogging through his Infantry Basic Training at Fort Benning, Georgia, reported that his standard rifle was a flat-topped M4A1 with flip-up iron sights.

War Story, M4

The police pursuit went on for more than four hours and covered 139 miles. Despite repeated efforts by negotiators to talk the suspect down via his cell phone he continued to threaten officers and express his willingness to die. After running over two sets of spike strips the suspect’s vehicle was finally disabled.

As officers exited their vehicles, the suspect fired twice with a high-powered hunting ri-fle. One officer returned fire with four quick semiautomatic shots from his M4 directed blindly through the right rear of the vehicle. He thought at the time he had only fired three. One round passed through an intervening automobile window and seat to strike the perpetrator in the back of the head, instantly incapacitating him. The man died later at a local hospital.

The M4 on the Range

The M4 chassis is indeed almost as slim and svelte as the CAR-15 that inspired it. However, after we stack lights, lasers, electronic optical sights, iPhones, video game consoles, and microwave ovens onto the forearm rails, the thing weighs about as much as a BAR. While I like microwave popcorn just as much as the next guy, it is easy to get carried away with that stuff.

The upside to all of the front-mounted tactical bling is that a properly tricked out M4 is absolutely sedate on the range. Mount something portly like an M203 grenade launcher on the rifle, and the gun will keep a full auto mag dump in a silhouette at twenty meters with only the most rudimentary attention to technique. With an EOTech Holosight perched a top the rifle and a Surefire X400 light/laser combo on the rails, the gun does things of which its Vietnam-era predecessors might only have dreamt.

The 14.5-inch barrel indeed strikes a nice balance between proper velocities and room clearing stubbiness. Losing that 5.5 inches costs you about 200 feet per second at the muzzle, but the extra portability is awfully nice in tight quarters. The M4’s ergonomics are unmatched, and in the right hands, literally nothing in the world runs faster.

Ancillary Weirdness

Gene Stoner could never have imagined the extraordinary course his revolutionary rifle would take once it left his gentle affections. There have been around 8-million M16 rifles in military use worldwide, and 90% of them are still in service. There are currently around 10-million legal semiautomatic AR-type rifles in circulation in America, and US industry has subsequently done some of the most amazing things with the design. Adequately cataloging all of these many variants would be an insurmountable task.

Stoner lived to see the rifle he had designed in the 1950s evolve into a newly imagined weapon before he died in 1997, but the ensuing 20 years have seen it completely evolve into the most versatile close combat tool the Free World has ever seen. However, the designs he conjured will likely arm the forces of freedom in their military, Law Enforcement, and civilian guises for generations to come. In the many-splendored versions of Stoner’s original Black Rifle, we indeed see an unfiltered example of Darwinian evolution in action.

Performance Specs

ARMALITE AR-10 Iron Winchester 147GR FMJ 2682 1.7
M16A1 Iron Tulammo 55GR GMFJ 3007 1.53
CAR-15 Iron Tulammo 55GR FMJ 2550 2.58
AR-18 Red Dot Tulammo55GR FMJ 2963 1.43
M4 Carbine Holosight Tulammo 55GR FMJ 2807 0.53

Technical Specs

WEAPONS/Barrel Length/Overall Length/Weight/Capacity/Rate of Fire
ARMALITE AR-10 20.8” 41.3” 8.9 lbs. 20 700
M16A1 20” 39.5” 6.35 lbs. 20/30 750
CAR-15 11.5” 33.6” 6 lbs. 20/30 750
AR-18 18.25” 38” 6.7 lbs, 20/30 750
M4 Carbine 14.5” 33” 6.36 lbs. 20/30 750

Velocity=Feet per Second=Average of 3 rounds measured 10 feet from the muzzle by a Caldwell Precision ballistic chronograph. Group Size=Inches=Best four of five rounds measured at fifty meters.
FMJ=Full Metal Jacket

Notes: This was an apples-to-oranges comparison. The AR-10 has seen a great deal of corrosive ammo. The barrel to the CAR-15 was bought well used in 1983. Additionally, the various sighting systems were far from equal.

This article first appeared in Small Arms Review V21N1 (January 2017)
and was posted online on November 18, 2016


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