Many people look at a modern sporting rifle and automatically assume it is an AR, but they may not understand what truly makes a real AR. A lot of manufacturers claim to make an elite product, but they are not held accountable for that. For those of you who take shooting and training seriously and want to purchase a high-quality firearm, you need to understand what to look for when you are evaluating a rifle.
Before you invest in one, let’s examine the design points that make up an AR or M-4, and which companies typically abide by industry standards. With a little knowledge, you can better understand what to look for when you purchase an AR-15.
There are several modern sporting rifle manufacturers, and you can typically see which one produced your weapon by examining the rail. If you are looking at a rifle you do not recognize, check there to see if you can identify the manufacturer. An even better way to analyze your weapon is by examining the particular components that make up the gun.
An extremely important part of the AR-15 is the Bolt Carrier Group. This is arguably the most vital component of the AR-15 uppers. The BCG consists of a carrier and a bolt gas key, as well as a few other components such as the cam, the firing pin, the firing pin retaining pin, the extractor, and the extractor pin.
The BCG is an important component because it performs a lot of the work for the rifle. It is responsible for feeding and extracting rounds–the basic action of the entire firearm. A true M-4 Bolt Carrier Group is heavier than the typical civilian versions on an AR-15.
The M-4 features steel that is even on both sides and on the ends; additional steel on the M-4 is not routed or hollowed out. These heavier BCGs are more reliable at feeding and reciprocating weight to force and extract deformed and uneven brass rounds through the chamber.
In addition, they handle dirty and sticky rounds better. Heavier bolt carriers’ increased “lock time” aids in extraction and feeding, reducing the felt recoil and reducing wear on internals, which are all positives for your weapon.
The larger portion of the bolt carrier is made out of steel and is a shrouded carrier. The firing pin should barely be visible and the interior should be chrome-lined. The outside of the BCG should be entirely parkerized.
The measurements for the AR-15 should be in accordance with original U.S. design, and the bolt should be made of Carpenter #158 Steel. The extractor should be made out of tool steel, and the pin that holds the extractor into the bolt made out of S2 tool steel. A mil-spec gas key that is heat-treated, hardened, and chrome-lined should be on the top.
Grade 8 fasteners should hold the gas key in place and be flush and properly staked–metal touching and impinging on heads. This is extremely important to keep the gas key from coming loose and initiating a misfire or malfunction of the weapon. If the gas key is loose it could render your rifle useless, so you will want to double-check your stacking marks and impinging parts.
Another aspect to note is whether your extractor insert is black or blue. High-quality extractor inserts are generally black. They will be magnetically particle inspected as well. This means the manufacturer will attach magnets to your rifle and sprinkle metal dust on it to find imperfections. Check for the “MP” to make sure that your rifle has been inspected for critical component damage during the manufacturing process.
Another important piece to examine before you purchase an AR-15 is the barrel. There are several identifying marks on a good AR barrel. You want to check for a “C” to determine if it is chrome-lined and to check again for the “MP” to make sure it was inspected with magnets for imperfections.
Additionally, you want to make sure that the barrel is made out of top-grade steel, generally a Chrome Moly Vanadium (CMV). Typically, these barrels are tested with an M197 round to verify that they can withstand high pressure. The MP testing is generally performed after this firing to confirm that the pressure did not create any flaws or cracks.
An important aspect to pay attention to in the manufacturing company is whether or not they perform batch testing. Not every manufacturer performs individual tests on all the rifles; some only run batch tests.
In this format, only about one out of every two hundred weapons is actually tested for accuracy and performance. It is important that your specific firearm is inspected before it leaves the factory, because you do not want to purchase one that has a flaw.
The third piece to examine on your AR is the barrel. The very bottom of every barrel should have two feed-ramps. Look for feed-ramps in a chrome-lined chamber and bore that are lowered and beveled. They should be smooth in order to allow rounds to easily ride up and out of the magazine and into the chrome-lined chamber.
On your front sight, you want to check for the “F” stamp to verify that it is the appropriate height for your rear sights. It also determines if it is compatible with any backup iron sights or additional sights you wish to incorporate onto your rifle. There should also be taper pins holding the front sights in place; this is a good indication of the quality of your front sights and that it is built to industry standard.
The AR-15 Lowers generally do not have as many aspects to evaluate. Most are made from a 7000-series Air Force grade aluminum. This is the standard mil-spec. The buffer tube is also standard–1.14” diameter receiver extension. There are two different diameters, and the 1.14” in mil-spec is stronger; the commercial version is not as sturdy.
Additionally, you want a buffer weight that is stamped with an “H” or an “H-2” on it. “H” is typical for most lengths and used for the AR-15. Furthermore, the Castle Nut is important to have properly staked to keep it from rotating out. A loose Castle Nut for non-staked lowers can potentially cause some issues with your rifle.
Those are some basic specs to look for when you are assessing which AR you want to purchase. Some major companies that generally adhere to these standards and specifications are Daniel Defense, Bravo, and Colt.
There are several others out there who follow these specifications too, so do your research on the manufacturing company of your next AR. If you need help purchasing your AR-15, check out Grab A Gun’s layaway program for gun financing!