The AR-15 was originally designed by a company called Armalite in the 1950s. It eventually became type classified the M16 by the U.S. military during the Vietnam War. Now, the name AR-15 refers to civilian legal semi-auto variants of the military M16 and M4 rifles. The AR-15 system is the longest serving service rifle in U.S. military history. It has served in one form or another for the last 49 years at the time of this writing.
The standard chambering for the AR is 5.56x45mm NATO. The commercial equivalent is .223 Remington although there are subtle differences between the two that shooters should be aware of (see further reading section below).
The AR-15 utilizes lightweight alloys and polymers in its construction to reduce weight and cost of manufacture. The receiver is aluminum while the grips and stocks are polymers. The barrel, bolt carrier group, and fire control group are all steel. A basic AR-15 weighs between seven and eight pounds unloaded.
Barrels range from 10″ to 24″ in length. On civilian legal fighting rifles, we are looking at barrels between 16″ and 20″. Rifles with barrels shorter than 16″ must be registered as Short Barreled Rifles (SBR) with the BATF.
The AR operates on a principal commonly called direct gas impingement although that term implies that gas is simply blown onto the bolt to cycle the action which isn’t quite true. What is true is that the AR-15 does not use a piston system like its predecessor the M-14 or most of its competitors around the world. Instead, high-pressure gas is directed out a port in the barrel, down a gas tube, into the bolt carrier. Inside the bolt carrier, the gas expands pushing the bolt carrier rearward. As the bolt carrier moves it rotates the bolt, unlocking it from the chamber. The bolt carrier continues to move rearward taking the bolt and spent case with it. The spent case extracts out the ejection port. A spring in the receiver extension (inside the stock) forces the bolt carrier group forward again, displacing a new round from the magazine and feeding it into the chamber.
The stock sights on the AR are quite good. They employ a post front sight and an aperture rear sight. A2 style sights are adjustable for elevation to adjust for ranges out to 600-800 meters depending on your particular rifle.
The controls on the AR are quasi-ambidextrous by default. While designed for a right handed shooter in mind they can be used by lefties with a slightly different manual of arms. On A2 and later rifles, there is a brass deflector behind the ejection port that deflects the brass forward and away from the shooter’s face while firing left handed.
The stock USGI magazines for the AR-15 are aluminum and come in 20 and 30 round capacities.
The AR Advantage
In the beginning, the principal benefit of the AR-15 over its predecessors was its light weight and ease of handling. In the Jungles of Vietnam, ranges were short, and fire superiority was favored over long range terminal performance. Its range is certainly sufficient, however, for most encounters either by soldiers or civilians. Marines have been training to hit man sized targets with this rifle at 500 and have done so for decades.
Since the AR has recoil, it is easy to learn to shoot well. Because the ammunition is less expensive than most other centerfire cartridges, you’ll be able to practice more. That also means you’ll be able to stock up affordably for that rainy day.
In the last ten years, the AR platform has truly evolved into a 21st-century weapon system. Accessories are now available to allow you mount lights, lasers, and night vision optics to your rifle. Collapsible stocks are now common which allow you to easily fit the rifle to you. Polymer magazines are now being built that can survive being run over by a truck. There have never been more options for the civilian shooter looking for a military pattern rifle than there is now with the AR-15.
Optics are also easier to mount on the AR-15 than some other platforms provided you start with a “flat top” model. Some people are opposed to optical sights, either red dot scope or telescopic, but I feel that anything that improves hit probability is a good thing.
The ergonomics on the AR are second-to-none. The controls are all easy to reach right from the firing position. Because it can be so compact the AR can be good for both indoors and out.
Given that the design is now almost 50 years old, the patents have expired. Dozens of companies are now building them. Parts and complete rifles can be found anywhere. Even Wal-Mart is selling ARs in certain parts of the country. This is a great thing if you are a high volume shooter or planning for hard times. I am convinced the AR-15 is easier to keep running for the average citizen than any other rifle available on the U.S. market.
About AR Reliability
Due to a less-than-graceful entry into service during Vietnam, the AR has poor reputation with some folks that continue to this day. Much of the issues with those early rifles were due to bureaucratic incompetence. Once the Army issued cleaning kits and resumed chrome lining the chamber and bore of their rifles the problems went away.
One of the things you need to do to keep your rifle running strong is lube it properly. Some folks think that running the rifle dry helps keep dust and powder residue out of the weapon. This is wrong. The weapon will accumulate filth from firing and being carried regardless of how it is lubed. Dirt that is lubed, however, is a lot slicker than dirt that is dry. Keep the rifle wet, and it will keep running for a long time without fuss.
Part of the problem with military rifles is that they shoot them until they break. Generally the military does no preventive maintenance on their weapons so troops carrying older weapons often experience problems. If your life depends on a weapon won’t you replace the springs and wear parts at regular intervals to ensure reliability? This is common practice with handguns used for duty by law enforcement and it needs to be standard practice for duty rifles as well. I may cover part life and replacement intervals in a future article. In the meantime a simple Google search should find you the information you need.
Lastly, make sure you get good magazines. I recommend USGI or Magpul mags. There may be some others that work but I have no experience with them. There are a lot of poor quality mags out there made by third rate companies. Do a little research before making a purchase and you’ll be able to avoid any heartache. Number your magazines so that if one starts to cause malfunctions you can isolate it. Mags are consumable items so keep a fresh supply handy.
What to Buy?
Choosing a rifle is a highly personnel thing. I will provide some general recommendations that apply to those looking for a hard use gun. If you are looking for a plinker then what you buy doesn’t matter much.
First choose a rifle from a reputable manufacturer. Dozens of companies are building ARs but only a few really build hard use weapons. Companies you should look into are Bravo Company Manufacturing (BCM), Colt, Daniel Defense, Knights Armament, Lewis Machine & Tool (LMT), and Noveske Rifleworks. These companies build their rifles to a standard so that you know what you are getting. They also use the quality control measures necessary to ensure a quality product leaves their doors. Many other companies don’t.
I would choose either a 16″ or 20″ chrome lined barrel. I have come to prefer 16″ as it is a handier length and doesn’t give up too much velocity. The chrome lining is much harder than plain steel which improves barrel life. It is much easier to clean also than plain steel. There is a lot of consternation on the internet about the accuracy of chrome lined barrels but most of this is nonsense. If you and your rifle can consistently shoot 4″ groups at 100 meters (4 MOA) than you can probably hit a man sized target at 500 meters. Most chrome lined barrels will shoot 2 MOA with decent ammo. How much more accuracy do you need?
Your bolt should be high pressure (HP) tested and magnetic particle inspected (MPI). This is a requirement on military rifles and it ensures that there are no defects in your bolt. You want a defect free bolt since it has to hold back up to 62,000 PSI of pressure with each shot.
Fixed stocks work but I much prefer a collapsible stock. Being able to adjust the stock on the fly helps with getting into different positions and allows you to adjust for the clothing you are wearing. The A2 stock is too long for many, if not most, shooters.
Get a flat top rifle so that you have the greatest flexibility in mounting sights and optics. While it is true that optics can be mounted on top of carry handle sights that arrangement prevents you from getting a proper cheek weld. Your accuracy will suffer accordingly. If you want to start with standard sights then buy a detachable carry handle that way you have options later.
Many rifles today come with free floating rail systems. Floating the barrel can improve accuracy. More importantly, these rail systems allow you to mount accessories such as sights, lights, and sling mounts. They are highly customizable. Non floating rail systems are also available and are easier to install and remove. If you opt for a free float rail make sure you understand how to disassemble it for maintenance.
Buy good magazines. USGI aluminum is OK but they do not take the punishment that the newer polymer mags can take. Since magazines are a weak point in any weapon system it pays to buy the best up front. Magpul P-Mags are both affordable and highly reliable.
The AR-15 isn’t perfect but nothing ever is. Every choice involves compromises. After a half century of use the faults of the AR system are well known and industry has solved most of them with product improvements. The others can generally be mitigated with training and knowledge of how the system works. There are a lot of alternatives to the AR but none of them are truly revolutionary systems. Dollar for dollar the AR performs as well as anything out there.
This guest article was written by Douglas Brooks. He is the founder of ProReviewly.com. He was enthusiastic about hunting from the first shot. He is also Rifle optic guru.