The Why Of The AR-15 Semiautomatic

By Jerry Stordahl
©Copyright, Precision Shooting Magazine

Bolt action rifles in general will overlap into other uses, and the semiautomatic AR-15 shares the same useful trait. The AR-15 has endured a rocky trail from its inception, but in today's shooting climate, it has become one of the most popular platforms ever produced.


The AR-15 has been maligned by the media, attacked by politicians, and even some in the shooting world have assaulted the "black rifles." They've come up with the misnomer, "assault rifle" to mislead and insinuate that these firearms possess some inherent evil. But every firearm's sole purpose is to serve as a cartridge firing platform, and that includes the popular AR-15.

The history of the rifle in general has shown that it is a tool of multiple uses. The pioneer or settler killed game to feed his family. He used it to protect lives and property, and he in some cases, brought it to military engagements against a common enemy. In the American Revolution, the muzzleloader was the quintessential martial arm.

So why do men own AR-15's or any other pseudo-military semiautomatic rifle? There are several valid reasons to own these rifles, but riflemen do not have to explain their ownership. The second amendment is valid today and attaches no distinction between black rifles or others.


The number one reason for owning an AR-15 carbine or rifle is for self defense. The original M16 was designed from the ground up as a military arm to be used by soldiers, and it had a bunch of problems that needed to be addressed. Since then, it has been studied, redesigned and refined. It has become an extremely accurate platform, and today it is better than ever. These refinements have transferred to the semiautomatic AR-15s in civilian hands.

So why are these arms purchased, accessorized and fired thousands of times in the United States every year? The AR-15 is acquired as a hedge against attacks by criminals or a rogue government. Whether this role is reality or imaginary is left up to the individual, but with the spread of terrorism, drug wars and hostile legislation, the prudent citizen prepares for defensive capabilities. The defensive task also includes the selection of the AR-15 for duty use by police officers. The role is similar, that of protecting lives. Though this article will deal specifically with the AR-15, there are great numbers of shooters who also choose the venerable AK-47, M1A, FAL, Garand, HK91 and 93 and other semiautomatic rifles.

The potential defensive role of the AR-15 defines its characteristics and further answers the question why? Because of features like collapsible stocks and short barrels, semiautomatic carbines can be maneuvered easily in tight quarters. Repeat shots are fast and simply accomplished with the press of a trigger. Recoil is minimal, and magazines can be swiftly changed. Maintenance and parts replacement can be successfully completed by a knowledgeable owner with a minimal assortment of tools.

The ergonomics of the AR-15 are unsurpassed by any other semiautomatic design. That does not mean the design is perfect. It means the controls are easily reached and manipulated. The platform is easy to shoot and transport. I have found in side by side testing, that a McMillan A5 stocked bolt action rifle is superior for pure ease of shooting off a rest or a bipod. That is due to the weight of the rifle and the ergonomics of the McMillan A5 -- namely the wide fore-end and the shape of the pistol grip.

But that's not the AR-15's role. It has not been purposefully designed for benchrest capability. It offers handling and shooting ease in a fairly light package for the moving rifleman, the citizen defending his property or the law enforcement officer. Fast handling, speedy shooting, light recoil and rapid magazine changes are four characteristics that make it suited for its purpose.

Still other motivations and "why" factors include the accuracy available within the parameters of the AR-15 design and the varied "style" options. We can have close range carbines, built up "game" guns, competition rifles and heavy-barreled varmint rifles. These are all reasons that help explain why the AR-15 has become so popular.

Both rifle and carbine models can be superbly accurate…probably more accurate than most field shooters. The accuracy of today's ammunition and rifles is at its highest point in the history of the rifle. The most popular accessories and components have been battle tested in Iraq and Afghanistan. Shooters buy accoutrements in huge quantities. This giant market not only offers wide selection, it helps drive America's economy.

With the defensive role as the most important, what other reasons could there be for owning the popular AR-15? What about pure enjoyment? There's a lot of fun involved in firing cartridges whether it is one or a whole magazine…or several magazines! It offers the same type of satisfaction that a benchrest shooter experiences when all the bullets punch the same hole.

Semiautomatic rifles aren't used in benchrest matches, so accuracy becomes relative. We want all the accuracy we can get without sacrificing reliability. A carbine does not need to be as accurate as a rifle used for long range, but the AR-15 can be very accurate with the right bullets.

As for accuracy, I have been firing a Colt HBAR Elite, which is Colt's AR-15 answer for use as a varmint shooting tool. With a 1/9 twist and 24 inch stainless steel heavy barrel, it will easily keep most generic loads under one inch for five rounds. That isn't anything special, though. With selected bullets, such as a 60 grain Hornady V-Max over 26 grains of Winchester 748, Winchester brass and Federal GM205M primer it will regularly punch .5 inch groups for five rounds and .6 or .7 inches for ten rounds. This load will yield around 3060 ft/sec. muzzle velocity.

Earlier I wrote that carbines did not need to be as accurate as long range rifles. That is because they are intended to be employed in close range situations, where pinpoint accuracy is not supremely necessary. Certainly accuracy is still desirable as hits can not be achieved without some degree of it.


The carbine versions of the AR-15 will usually be fitted with Aimpoint red dot sights or Eotechs or a low powered scope. These optics are geared for speedy shooting at close ranges, rather than pinpoint accuracy at the longer ranges. However, a skilled shooter can accomplish great feats even with red dot sights or 1-4 power scopes.

Accuracy is great, but reliability is what shines when it comes to AR-15's. Reliability is important in any firearm, but it is especially critical in one used to defend lives. The AR-15 used for defense must work every time, or the consequences could be disastrous. That is why it pays to do the research before purchasing a particular firearm or accessory. Keep things simple, and look for quality before price.

For the defensive role, I would select a carbine model that would offer the extra security of a magnetic particle tested bolt, a chrome lined 1/7 or 1/8 twist barrel of 4150 steel and the proper 5.56 chamber for reliability. With the extra steps taken in the inspection process, the marksman will not have to be concerned about hidden flaws, which could generate a malfunction at the wrong time.


I'd take a hard look at a Colt, LMT (Lewis Machine and Tool) or Noveske built gun. The Noveske AR-15's offer models with stainless steel barrels, too. In addition, there are several "custom" builders who use excellent parts and put together extremely accurate, reliable rifles. You pick your flavor and pay your cash. If you've already picked another brand, just make sure the bolt carrier key screws are properly staked. Also, on adjustable carbine stocks, check for staking on the castle nut. Parts can loosen with use and cause malfunctions, and they could occur at the wrong time.

The flat top configuration with the removable carry handle/rear sight is the most desirable. The flattop design makes the AR-15 more versatile, and if you still want to use the iron sights, just leave the carry handle installed.

The AR-15 trigger is designed to be used under harsh conditions. It's not going to "feel" like a match trigger, especially in a carbine used for defense. A shooter can expect a 5 to 8 pound trigger release and sometimes heavier, which fits within the military technical parameters for these rifles.

My carbines fall into this "standard" range, and my Colt HBAR Elite utilizes a stainless "enhanced" trigger. The enhanced combination comes with a lightened hammer and teflon coated springs. It breaks at a fairly clean 5 pounds, and it is very satisfactory in performance.

There are several AR-15 triggers available on the market for a variety of uses, and these all have their place in the overall world of shooting the AR-15. Geissele's offerings are well known and respected trigger/hammer units that come highly recommended by many AR-15 users. There are others from Accuracy Speaks, Chip McCormick, Timney, JP Enterprises, and the list can get quite long. I still maintain that for home defense use, a carbine with a standard trigger is best. The standard trigger is rugged and won't lose adjustment, because there is none. That makes it reliable and foolproof.

Whether mounting Aimpoints or conventional optics, some of the best solutions for doing so are manufactured by Larue Tactical. The Larue quick release mounts are finely machined and anodized aluminum, and the lever tension is adjustable. The Larue LT-104 SPR-1.5 mount is the one I use on the Colt HBAR Elite. This unit allows the optic to be positioned far enough forward to gain proper eye relief, and this attribute is more important to me than the quick detachable feature. There are lower and higher versions available, and there are also extended models offered. There are other quality mounts for attaching optics on the AR-15, so a shooter has to explore the options and then decide what fits his needs.

On my carbines, Larue quick detachable mounts hold Aimpoint M2's, and Larue back up sights are fixed in place. At one time the M2's were the latest and greatest, but Aimpoint has newer models now. I've seen no compelling reason to change, however. The advantage of the newer models will be longer battery life and a choice of a smaller 2 m.o.a. red dot. I like the 4 m.o.a. sized dot, because it is fast and easy to see.

Some shooters employ folding sights for a cleaner view through the Aimpoint, but the Larue sight is always ready. I believe a backup sight should be instantly available, and there is nothing more instant than an upright sight aperture fixed in place. Folding sights such as the Troy Industries unit certainly have their place, especially when a magnified optic is used that must be placed over the folded sight to gain the proper eye relief.

Up front, the standard M4 configuration hand guards of my carbines have been replaced with Knight's Armament M4 RAS (Rail Adapter System) assemblies. Rails allow a light and/or vertical grip for shooter use, and there are many offerings on the market. I chose the KAC because of their reputation for quality, plus I wanted to be able to quickly remove the lower portion of the rail for wiping off the barrel should the need arise. To me the ease of field maintenance outweighs any gains in accuracy a free float assembly might offer for short range use.

Many of the free floating units require barrel or gas block/sight removal for installation. There are other rails available such as the Daniel Defense "Omega" that can be installed or removed without any disassembly. The Larue offerings in free float rails also have a large following, but these require barrel removal for installation.

A decent sling is a useful addition for retention of the carbine and also for normal carrying. I prefer a two point sling for my own uses, and my choice is the Blue Force Gear, Vickers Combat Applications Sling (VCAS). The quick slide adjustment is great, and the quality is excellent.


Also, there are several different collapsible stocks such as those from Magpul, Vltor and LMT that can replace factory units, if the shooter feels the need. Accessory choice is vast and is another reason for the why factor.

For ammunition to run the carbines in practice sessions, I generally just shoot any 55 grain loads I have around. A 55 grain bullet with 26.5 grains of Winchester 748 and CCI 400 primers will generate about 2740-2800 ft/sec. from a 16 inch barrel. For reference, the same load runs up to 3210 ft/sec. from a 26 inch Winchester varmint barrel, depending on the bullet and temperature.

For the most efficiency in the defensive role, 75 grain Hornady Match bullets are loaded over 25 grains of Varget for 2608 ft/sec. velocity from a 16 inch carbine barrel. CCI 400 primers and Winchester brass are utilized for these loads. The Aimpoint is zeroed at 50 yards, and the red dot sits on the top of the front sight when viewed through the Larue back up site aperture, for a proper co-witness.

I resize the necks of the new brass to assure they are uniform, then run them through a .244 inch Redding bushing. The normal neck measurement after full length resizing would be .245 inch, but with no crimping cannelure on the Hornady bullets, I put a little more neck tension on the bullet. Bullets are seated with a Redding Competition seater with its sliding alignment sleeve.

Please note that some AR-15s are chambered in .223 Remington, even though they may be marked as 5.56 chambers. The usual cautions apply in developing loads. Start a couple of grains lower and work up.

Fast magazine changes are one of the reasons for the AR-15's popularity, so plenty of magazines should be stocked for ready use. Good quality aluminum G.I. contract magazines such as manufactured by Okay or Brownell's, or the Magpul Industries synthetic ones should be selected. A magazine fed rifle loses its efficiency if there are no loaded replacement magazines at the ready, and a poor or damaged magazine will lead to malfunctions. Most shooters already know this, but with the AR-15 selling in record numbers, there may be a lot of new owners out there.


It is essential to carry extra loaded magazines, depending of course on the situation. For a ready to go carrying unit, I like the Eagle M4 Patrol Bandoleer. It is simply a compact pouch with a strap that can be grabbed and quickly slung over the shoulder. It will hold four thirty round magazines, and on each side of the double mag pouches there is a smaller pocket for pistol magazines. I carry a Gerber multitool in one of the mag pockets.
This carrier can be stored next to the rifle so extra magazines will be available for transport, should a person need to take up arms. A small loop on the back can secure the unit to a belt to help stabilize it.

Competition shooting is another field where the AR-15 has made great inroads. The AR-15 rifle successfully competes at the High-power Service Rifle matches by making use of .224 inch heavy bullets. What makes the AR-15 so grand in this application of competition shooting, is that it can be fired accurately enough to win! Courses of fire include ranges of 200, 300 and 600 yards! And that is another reason for the why! There are trigger pull weight restrictions and other rules, and this data is available from the NRA website.

Earlier in this article I mentioned using a rifle for varmints, and that brings to attention another valid rationale to own AR-15 rifles. That reason is hunting, and it is part of our national heritage. The .223 cartridge is limited in its power application on larger animals, but there are plenty of configurations available that are suitable for nearly any size of game. I am thinking of the .50 Beowulf, the .458 SOCOM, the 6.8 Remington and others.
The .223 cartridge has been used to take deer, and I am sure it will continue to be used for that purpose. Successful use means utilizing the proper bullet for best results. Winchester offers their 64 grain Power Point and Nosler has the 60 grain Partition. There are other bullets from Barnes, Speer and Sierra that a shooter can study and try. The construction of these smaller bullets is important when used on deer-sized game as is shot placement. I prefer to use a larger caliber and cartridge for deer hunting…namely the .308 Winchester. Check applicable state game laws, also, because the little .223 Remington may not be legal for deer hunting in every state. But you can change that by pushing out two pins and adding a caliber legal upper assembly! That is versatility at its best.

The AR-15 platform runs well, but like anything with moving parts it needs lubrication and cleaning. For lubrication I'll use Breakfree CLP or Slip 2000 or synthetic motor oil. The AR-15 is not fussy about lube as long as it gets some.

Every rifle's purpose is to chamber a cartridge and launch a bullet. Where that bullet is aimed is up to the individual, and some just like to do it with self loading capability. AR-15s have been called ugly, black, evil "assault weapons" by liberal politicians and various media sources. They have attempted to vilify these enjoyable firearms, and I doubt it would help to paint them fluorescent orange. It's not the color "they" hate! It's the capability of resistance to their agenda. So…why a semiauto? My answer is…why not? The second amendment is still valid today!


Brownells, Inc.
200 South Front Street
Montezuma, IA 50171

Larue Tactical
850 County Road 177
Leander, TX 78641

Eagle Industries
1000 Biltmore Drive
Fenton, MO 63026

Blue Force Gear, Inc.
P.O. Box 853
Pooler, GA 31322