I think you’ll have an easier time building one after you’ve spent some time with a factory gun.
For those who have graduated from the factory-built AR-15 and want to build your own AR-15 lower receiver, there are several resources out there that will walk you through the process.
I recommend this helpful and informative YouTube video, which covers the process start to finish.
This is another important area that needs to be covered, especially for first-time shooters. We’ll begin by breaking down the AR-15 system by talking about the multiple characteristics of barrels.
The chamber is that part of the barrel where the cartridge resides before it is fired. This, and the barrel itself, determine what kind of ammo your rifle can shoot.
For beginners, you’ll want to focus only on the most common loads— the .223 Remington and the 5.56X45 mm. As mentioned earlier, there are lots of rifle calibers available for the AR-15, from the lowly .22LR to the powerful .50 Beowulf, but the .223 Remington and the 5.56X45 mm are the two best offerings for novices.
The 5.56mm is the most popular choice for home defense and fun plinking sessions. It is readily available so ammo is cheap.
Now this might seem like a no-brainer but when it comes to guns, safety should always be a top priority. With that in mind, here are some guidelines first-time AR-15 owners have to remember:
With a .223 barrel, you can only fire .223 rounds.
Hybrid chambers like Wylde are implemented for specific reasons but can fire a .223 or a 5.56.
The 5.56 barrel, on the other hand, can fire both 5.56mm AND .223 Remington
Always clean and lube before shooting, especially if your rifle is new.
Always protect your eyes and ears with goggles and ear plugs
Consider taking shooting lessons/classes before purchasing an AR-15.
The minimum barrel length, according to Federal law, is sixteen inches. If an additional device is used, such as a muzzle brake or flash hider, it has to be permanently attached if it will be included in the rifle’s length.
For instance, gun owners can have a 14.5-inch barrel and weld a muzzle device that’s 1.5-inch long in order for the gun to be compliant with Federal requirements.
However, it is important to note that some states and municipalities have their own laws governing firearms and their accessories, so be sure to familiarize yourself with the rules and regulations in your area.
Due to these restrictions, we strongly advise first-time shooters to purchase at least a sixteen-inch barrel so that they can swap out muzzle devices at will. There are three main lengths that are popular: 16”, 18” and 20”.
One thing that beginners should be aware of is the length of an AR-15’s barrel doesn’t necessarily equate to accuracy. Anyone who knows that they’re doing can achieve plenty of accuracy with a sixteen-inch barrel because it is stiffer and thus less affected by barrel whip.
On the other hand, longer barrels can provide higher velocities as there is more space for the powder to burn and more room for the bullet to accelerate.
When bullets are able to move faster, there is far less time for environmental factors to affect the bullet’s trajectory (e.g. wind and gravity), meaning that each shot will be relatively more powerful and a bit more accurate over longer distances.
On average, sixteen-inch barrels are able to reach a target from four hundred yards away. That being said, the traditional fifty-five grain load grows more imprecise after three hundred yards, so fire carefully.
If you’re looking to fire at a longer range, you would fare better with a heavier, longer load like a sixty-two grain, seventy-seven or eighty grain bullet.
When I’m considering a weapon of any kind, I always think about portability. Shorter barrels generally weigh less and are easier to handle.
When you first get into guns, it can be overwhelming. There are so many numbers and so much technical jargon that it might seem scary or confusing.
This is especially true of barrel material which is why I’ve tried my best to simplify it for the newbies out there who are just learning about this stuff.
4140: This consists of steel with ten percent less carbon compared to its predecessor, 4150 steel.
4150: Steel used in mil-spec barrels.
Stainless Steel: This one is more accurate but isn’t as durable as 4150 or 4140 steel.
Chrome Molybdenum Vanadium, Chrome Moly, or CMV: Basically identical to 4140
There are slight differences between that last one and 4140. Chrome Molybdenum Vanadium steel alloy contains a range of elements from chromium and nickel to molybdenum and so forth. It is renowned for its strength and hardness.
“Chrome Moly” or Chromium-molybdenum steel, is a range of low alloy steels that are of high tensile strength and aren’t as lightweight as counterparts like aluminum.
4140 alloy steel is a combination of chromium, molybdenum and manganese has high fatigue strength, impact and abrasion.
Both are high tensile strength steels which make them great for guns as well as bicycles and the like.
The average shooter should probably just stick with 4140 or CMV because there’s really no benefit to using 4150 unless you’re dealing with a fully-automatic piece. Besides, you’ll save money as 4150 costs more.
There are three basic options on the market when it comes to the inside of your AR-15 barrel. They are as follows:
Ferritic Nitrocarburizing (FNC): Otherwise referred to as Melonite, Tennifer or Nitride, FNC treats the surface of the barrel instead of just coating. This can result to increased accuracy.
Chrome Lined: A popular form of barrel lining. It is a coating that makes for better barrel longevity, but that longevity comes at a price — accuracy might suffer. If either end of the barrel has a gray ring around it, it’s chrome lined.
None: Some barrels have absolutely no coating whatsoever.
Many environmental factors such as heat, moisture and more can affect your exact round count, but you can count on approximately ten to twenty thousand rounds before you need to re-barrel.
If you’re still with me, let’s move on to testing, another important area to be aware of.
As I said before, there is a lot of technical mumbo jumbo that comes with owning guns. Some acronyms that manufacturers like to throw at you include the following:
MP: Magnetic Particle tested. This just means that it’s essentially subjected to X-Rays to check that the gun doesn’t have any voids, cracks or other imperfections.
HP: High Pressure tested. This is a method by which manufacturers ensure the integrity of anything from primers and projectile seating depth to chamber parameters and neck tension.
Of course, some AR-15s have not been tested at all, so buyer beware! If a gun’s packaging or advertising specifically says it hasn’t been tested or doesn’t mention testing, you’re buying it at your own risk.
Cold, Hammer, Forged (CHF): This is a process that results in a more durable barrel. Repeated blows by a series of hammers align the grain within the metal, causing more strength and rigidity.
Barrel, Forged, Hammer (BFH): Essentially the same as CHF, BFH is where a mandrel (carbide tube) is inserted into the barrel, rotated and pushed forward to create precise rifling.
With these options, you lose some accuracy but they make up for that with increased durability.
This refers to the thickness and overall shape of your barrel. Fortunately, there are several options available.
CAR (Colt Automatic Rifle): This one used to be the name of a certain group of AR-15s and M-16s back in the 1970s, but today it is a name for carbine-length rifles.
Light: This one is just what it sounds like, it’s lighter than others but it’s vulnerable to the heat associated with rapid firing. This one’s .625-in in diameter.
Heavy (Bull): This one is heavier and stiffer, but it’s also far more accurate. I like this one a lot because it can handle more heat than others before it starts to be affected. It’s typically implemented for precision builds. Bulls are .936” in diameter.
Medium (M4): The M4 contour possesses a cutout for grenade launchers which is what makes it ideal for military purposes. It’s got terrific balance and is .750” in diameter.
In my opinion, the average plinker doesn’t require anything more advanced than light or medium barrel.
BARREL FEED RAMP
This is a vital part of the AR-15’s upper receiver, therefore you want it to properly match the barrel of your rifle.
It is still debatable as to whether or not the barrel’s feed ramp affects reliability, but at the very least, it’s important to match the ramp with the upper receiver. Usually, if you buy factory made rifles this won’t be an issue, but you should still check to confirm it.
AR-15 GAS SYSTEMS
Now that you know the basics of the AR-15, we’ll get into more complicated stuff.