When Eugene Stoner and his engineering companions at Armalite, and then Colt, designed the AR-15 rifle back in the late 1950s, I doubt they expected the rifle to see anywhere near the success it eventually achieved.
Their initial rifle, the 7.62x51mm AR-10, had been unceremoniously rejected during the 1957 U.S. Army Infantry Board trials on scurrilous grounds, and none of their subsequent designs had elicited much interest from anyone.
Clearly, the revolutionary design of their rifles repelled the military traditionalists in charge of weapons procurement.
Still, they persevered and scaled down the AR-10 to handle a new cartridge, the 5.56x45mm, developed specifically for it by Remington. The newly formed U.S. Navy SEAL and U.S. Army Special Forces teams showed interest in the AR-15, and when President John F. Kennedy, Secretary of Defense Robert McNamara and U.S. Air Force Chief of Staff General Curtis LeMay were impressed by it, things began to look up. Development of the AR-15 was fast-tracked, and the rest is history. The AR-15 was formally adopted as the “M16” in 1963; and, in one form or another, it has been the U.S. military service rifle ever since.
Over the 54 years it has seen service thus far, a number of different versions of the M16/AR-15 have appeared. Among them was a compact version known in the U.S. Army as the XM-177E2 and in the U.S. Air Force as the GAU-5, which appeared during the late 1960s.
The compact “CAR-15,” as the troops called it during the Vietnam War, was a combination of two of the guns of the original five-gun AR-15 system—one a survival rifle and the other a so-called submachine gun (although its rifle cartridge technically disqualified it from being a true SMG). The result was an exceptionally light, fast-handling little carbine with an 11.5-inch barrel and telescoping buttstock that quickly became a status symbol to the SpecOps personnel to whom it was issued. After Vietnam, Colt marked it as the “Commando,” a designator it still enjoys today.
The XM-177E2 muzzle blast was severe, and Colt reduced it to levels comparable with a standard, 20-inch-barreled M16/ AR-15 by adding what it called a “sound moderator.” In fact, it was technically a 5-inch, screw-on sound suppressor. Thus, if taken from military channels and placed in civilian hands, it was in violation of U.S. federal law. The problem was that U.S. troops quickly expropriated them to mount on their .22 rifles, causing a problem for U.S. authorities back home.
Consequently, after the Vietnam War was over, in order to rectify the problem, Colt eliminated the sound moderator completely and increased the rifle’s barrel length to 16 inches to approximate the overall length of the XM’s barrel with the sound moderator attached. This made it legal in civilian hands, because there was no “silencer” involved. Military versions were known as the M16A1 carbine, while the civilian AR-15 model was designated the AR-15 carbine.
Today’s M4 is essentially a third-generation successor to both the XM-177E2/GAU-5 and M16A1/AR-15A1 carbine and differs from the latter only in that its barrel is contoured to accommodate attachment of the M-203 40mm grenade launcher. Military M4s have a 14.5-inch barrel, whereas the civilian-legal model—sometimes jokingly referred to as the “M-4gery”—utilizes a 16-inch barrel to comply with federal law. Otherwise, the only other differences are that today’s M4 has the flat-top rail with detachable carrying handle/rear sight assembly and the 1-7 rifling twist of the M16A3/AR-15A3, whereas prior to 1985, the 1-12 twist and fixed carrying handle/ rear sight assembly of the M16A1/AR-15 were standard.
The AR carbine is one of the most ergonomically sound designs in firearms history. Like its predecessors, its magazine release button, safety/selector switch, bolt release, charging handle and forward assist assembly are ideally located for fast, efficient use under stress. In addition, its magazine well is wide and easily accessed for rapid mag insertions. In conjunction with its light weight and good balance, the AR carbine makes for a package that’s hard to beat.
MISSION DEFINITION AND ACCESSORY SELECTION
Of course, for any gun that achieves such notoriety, a booming accessory market for the AR carbine has appeared. As with the M1911 pistol, there is now a seemingly endless array of accessories available, some of which are useful. Others are not and fall within the realm of being “tacticool,” rather than being
something that actually improves the weapon’s efficiency.
A good example of this can be found with flash suppressors. There are literally dozens of them being marketed—some of which actually work … and some that do not. Yet, the AR’s original flash suppressor is more effective than most of them and is also a pretty good muzzle brake. In a tactical environment, muzzle flash is a serious issue; as a result, the military handled it with deadly seriousness.
Another good example is magazine capacity. Today, there are 10-, 20-, 30-, 40- and even 100-round magazines for the AR. However, magazine capacity is not the only consideration: The original AR-15 was designed around a 20-round mag to ensure good balance and handling qualities. As the years passed, 30-round mags became standard issue for the military as the result of an increased need for volume of fire. The 30-rounder was simply the most-tolerable compromise of utility and firepower.
Magazines with a larger capacity than 20 rounds can also cause other problems: They tend to snag on web gear and vegetation and get tangled up in tactical slings. In addition, for many shooters, they prevent a good prone position.
Tactical slings, too, should be viewed with caution. Their original creation was for military or SWAT personnel with the intent of allowing them to maintain physical possession of the rifle if they were forced to use their handgun or perform other functions requiring two hands, such as rappelling or fast-roping. If the person is “bulked up” with body armor, web gear or other equipment, tactical slings often tend to get tangled up in things at inopportune times. For a civilian in a self-defense situation or a police officer in a non-SWAT function, in my personal opinion, it’s difficult to see circumstances for which a tactical sling is of any real advantage.
KEEP IT SIMPLE
So, when you consider improving or customizing your AR carbine, be sure to first sit down and think about it. Clarify what you need before you do anything else, or you’ll join the ranks of those who “loaded up” their AR carbines with accessories that were useless for their needs—resulting in a serious debilitation of the weapon’s performance.
The military mission is more complex and diverse than civilian or law enforcement self-defense, so know what you absolutely need before spending too much money for little or no increase in performance. I’ve seen AR carbines so loaded up with accessories that they weighed a full 16 pounds, thereby completely destroying the weapon’s fast-handling qualities. By way of comparison, the old M1918 Browning Automatic Rifle [BAR] without the bipod attached weighs 16.5 pounds. If I’m going to carry a rifle that weighs that much, I’d rather have a .30-06 Springfield than a 5.56 NATO!
OPTICAL BATTLE SIGHTS
Optical battle sights are, without question, useful additions to any AR setup—but as with all other accessory items, be sure to define your needs clearly before you buy one. The Aimpoint, ACOG and EOTech holographic sights are, by far, the most popular and are used in great quantities by military personnel around the world. Still, each one has its strong and weak points, depending upon your needs.
For example, the Aimpoint and EOTech have no magnification and a relatively large aiming point, making them wonderful for fast work on large targets at close ranges. However, for partially obscured or small targets or targets at longer ranges, they’re not so efficient. They’re both also electrically operated and battery dependent, which, in my view, gives “Murphy’s Law” a little too much chance to come into play. I’ve seen it often enough for this to be of concern.
Conversely, Trijicon’s ACOG is more rugged and can be had with a variety of reticles that provide more utility for generalpurpose needs. I want my AR to be capable of handling the full spectrum of general-purpose missions, so hands down, I prefer an ACOG over any other type of optical battle sight. It’s also not electrically operated, depending instead on a tritium reticle or a fiber-optic for low-light reticle visibility.
Of all the ACOGs Trijicon offers, I find the TAO-1 the most efficient for my needs. In short, a properly selected ACOG is just as fast up close as an Aimpoint or EOTech, but it is superior at longer ranges and on small or obscured targets. Its drawback? Price. ACOGs are substantially more expensive than either an EOTech or Aimpoint. (Still, how much is your life worth?)
DIRECT GAS FEED OR PISTON DRIVEN?
Over the years, there has been some criticism that the direct impingement gas system of Stoner’s original design allows excess fouling to accumulate in the receiver area and bolt carrier key. Yet, over the multiple decades it’s been in worldwide use, the problem doesn’t seem to have been of epidemic proportions. Still, Stoner, himself, suggested the addition of a traditional gas piston to replace the original design.
So, at least in theory, there must be something to the claim.
For those who are concerned about it, many manufacturers make gas piston systems—both upper receivers and complete rifles. Piston systems reduce receiver and bolt fouling to almost nothing. They smooth functioning dynamics and, if nothing else, reduce maintenance to a minimum. As a result, many AR aficionados swear by them.
Accuracy is always important. As Colonel Townsend Whelen once said, “Only accurate rifles are interesting.”
Although military rifles don’t have to be tack-drivers to be effective (the AK-47 is a great example), as long as making the rifle more accurate doesn’t degrade its functional reliability, doing so is worthwhile. In my not-inconsequential experience with Stoner-designed rifles, I’ve found that for the best accuracy, a tight upper/lower receiver fit is needed. I’ve also found that a good, clean trigger is also critical, so I installed Accu-wedges and Timney 3-pound drop-in triggers in all my AR carbines and other ARs, as well.
If your needs include precision shooting, the AR carbine is capable of accuracy that rivals a heavy-barreled, bolt-action precision rig—if it’s properly modified. I have one that features a heavy, free-floated barrel, circular steel, ventilated handguard, a Timney drop-in 3-pound trigger, Accu-wedge and a Magpul MOE fixed buttstock and pistol grip. To this, I added a Leupold FX-1 8x40mm target scope with duplex reticle in a Leupold Mark II IMS rail mount. The result was that with proper ammo selection, the rifle is capable of ½-MOA accuracy. Enhanced as I’ve described, even the standard AR carbine is capable of 1 to 1.5 MOA, depending upon ammunition.
As for ammo itself, the best way to determine which is best for your needs is to first define those needs carefully. Then, try any prospective ammo to see how it functions and how well it shoots in your particular rifle.
Because my needs are general purpose, I have found that virtually any decent 55-grain SP shoots well in my AR carbines (I have a dozen of them in various configurations). However, I’ve also found that Dynamic Research Technologies’ (DRT) 55-grain HP not only produces excellent accuracy, it also delivers devastating terminal ballistics. Consequently, it puts the 5.56 NATO in an entirely different performance category, which, as a 5.56mm, it definitely needs.
The AR carbine is clearly a winner and will be with us for quite some time to come. Yet, like any other successful design, it can be improved upon if you clearly define your needs and pick your accessories, modifications and ammunition appropriately.
Colt’s Mfg. has traditionally named civilian versions of the M16 the “AR-15” series of rifles. In the instance of the military M4, Colt has also named the civilian version “M4.” In this article, when reference to the civilian M4 is not Colt specific, the term, “AR carbine,” is used.
A version of this article first appeared in the January 2018 print issue of Gun World Magazine.