5 Best AR-15's - Everything You Need to Know

Why Should you own an AR-15?

The AR-15 is arguably the most popular rifle in modern American history. Known for its modularity and widespread use its often considered essential to any gun collection. The AR-15 platform allows different upper receivers to be attached to a lower receiver allowing the user to quickly change barrel lengths and calibers. AR-15 parts are readily available allowing you to customize your AR-15 for different applications or different styles. The rail on top of the receiver allows a variety of optics to be mounted. This rail offers a distinct advantage over counterparts like the AK-47, M1A, G3, and FAL. Lastly, the essential things you need to run an AR-15 are usually always in stock during shortages, things like magazines and 5.56 ammo.

Where can I buy an AR-15?

You can buy an AR-15 online at MidwayUSA. We’ll ship the AR-15 directly to the FFL of your choice where you will have a background check before you can pick up your rifle.

How much does an AR-15 Cost?

AR-15s can cost anywhere from $500 to upwards of $3,000. Cheaper ARs usually have cheaper furniture that can be replaced later while more expensive ARs will just need an optic to be ready to go. The quality of essential parts like the barrel are also compromised the cheaper you decide to go. If you want an AR-15 from well respected firearm manufacturers like Ruger, Smith & Wesson, Sig Sauer, etc. you should expect to pay at least $700.

What does AR stand for in AR-15?

Contrary to popular belief AR does not stand for Assault Rifle but instead ArmaLite Rifle. ArmaLite was the original developer of the AR-15.


The AR-15 was originally chambered in 5.56x45mm but as time has gone on more calibers have become available. The AR-15 can also be chambered in 300 AAC Blackout, 9mm Luger, 22 Long Rifle, 7.62x39mm, 450 Bushmaster, and many others. If you are looking for larger cartridges the AR-10 is an AR style rifle chambered in longer cartridges like 7.62x51mm, 308 Winchester, and 6.5 Creedmoor.

Barrel Length & Gas System Length

The barrel length on a gun impacts velocity and as a result accuracy. Most AR-15’s have barrel lengths between 5 inches and 20 inches, although most barrel lengths will be between 10 inches and 20 inches. The AR-15 gas system length depends mostly on barrel length.

  • Pistol Length Gas System – Typically will have barrel lengths less than 12 inches. 300 Blackout uppers might have 16 inch barrels with a pistol length gas system.
  • Carbine Length Gas System – Typically will have barrel lengths between 10 inches and 16 inches. Two of the more well known military configurations that use the carbine gas system are the MK18 and the M4A1. The MK18 uses a 10.3” barrel while the M4A1 uses either a 14.5” barrel or a 16” barrel.
  • Mid-Length Gas System – Typically will have barrel lengths between 14.5 inches and 18 inches. There has been much debate on which gas system length is better on a 16” barrel, Carbine or Mid-Length. Most people agree that with a 16” barrel Mid-Length is the better option since it provides a better dwell time and is easier on bolt parts.
  • Rifle Length Gas System – Typically an 18” or 20” barrel. Two well known military configurations are the MK12 which features an 18” barrel and the M16A4 which features a 20” barrel.


The original handguards for AR-15’s did not have a way to attach accessories, over time quad rails became popular and more recently KeyMod and M-LOK handguards have become the most popular handguards. Some AR-15’s have a front sight base gas block that can make choosing a handguard difficult. When there is a front sight base you need to either get a shorter handguard or one that has a cut-out for it, like this handguard from Midwest Industries. A low profile gas block allows a longer and slimmer handguard, this allows the user to have more real estate when mounting accessories on their AR-15 along with a better hand position.

Barrel Twist Rate

The twist rate on an AR-15 is the distance it takes the projectile to make one full rotation. 5.56x45mm AR-15 barrels usually have a twist rate of 1:7”, 1:8”, or 1:9”. The 1:7” twist is the fastest making it ideal for heavier projectiles like 77 grain while the 1:9” is a slower twist making it ideal for lighter loads like M193 55 grain. Generally speaking higher quality AR-15’s will have 1:7” twists while more budget friendly AR-15’s will have 1:9” twists, 1:8” twists are usually in between budget and high-end.

Below we listed 5 of the best AR-15’s we carry that cover every category. We included a 20” M16 clone, 18” Daniel Defense MK12, 16” Colt M4, 14.5” Barrel AR-15, and a budget AR-15 that would be a great first AR-15.


FN FN15 M16 Semi-Automatic Centerfire Rifle 5.56x45mm NATO 20" Barrel Black and Black Fixed

Directly from the front lines to your collection, the FN 15 Military Collector Series M16 is a military replica rifle made to FN’s exacting specifications. The semi-automatic rifle is chambered in 5.56x45mm NATO and features a 20-inch, 1:7″ RH, button-broached, and chrome-lined barrel. The UID-labeled lower receiver is equipped with an ambidextrous selector switch, just like its select-fire big brother.


  • Ambidextrous selector
  • Knights Armament M5 RAS Adapter rail with rail adapter covers
  • Flat-top receiver MIL-STD-1913 rail at the 12 o’clock position
  • UID label

About FN

FN is a global leader in the development and manufacturing of high-quality, reliable firearms for military, law enforcement, and commercial customers worldwide. FN offers some of the best semi-automatic rifles and pistols on the market as well as individual firearm parts, accessories, and apparel. MidwayUSA carries several top FN products, including the Five-Seven, PS90, FN15, SCAR, and more. FN is passionately committed to providing dependable, innovative firearms of the highest quality to our customers who rely upon us to enhance their performance and safeguard their lives.

Shop Now

Daniel Defense MK12 Semi-Automatic Centerfire Rifle

The evolution of the SPR comes home to Daniel Defense in the MK12.  Born of necessity, raised in the Army’s Marksmanship Unit and refined to Daniel Defense Mil-Spec+ standards, it is now available. The MK12 is constructed around an 18-inch Stainless Steel barrel with a chamber created during the Cold Hammer Forging process, which ensures the most precise alignment of the chamber to the bore possible.  This, along with being DLC finished, equates to unprecedented accuracy and durability.  The MK12 barrel is engineered with a rifle-length direct impingement gas system and utilizes the MK12 gas block, which is built to Crane Specifications for USSOCOM.  The MK12 gas block is precision CNC machined from 416 stainless steel and Black Oxide Coated.  The rifle is fed with a M16 profile bolt carrier group and uses a BCMGUNFIGHTER Charging Handle for ease of operation.  The upper receiver is equipped with a free floating DDM4 Rail 12.0 quad rail for allowing your choice of optics and accessories and is finished off with a Daniel Defense Improved Flash Suppressor. The MK12 was designed from the ground up to be a precision rifle, therefore it required certain refinements.  We equipped it with the Geissele SSA 2-Stage Trigger to give the marksman an advantage delivering precise fire to the target.  The MK12 is also furnished with the rugged and comfortable Daniel Defense Buttstock and Pistol Grip.


  • Cold hammer forged barrel
  • 17-4 Stainless steel flash suppressor
  • Ambidextrous safety selector 
  • Free float handguard
  • Soft touch, overmolded adjustable buttstock
  • Soft touch, overmolded pistol grip
  • Three Low-Profile Rail Ladders
  • Cut and polished feedramps
  • Picatinny Rail
  • Flared Magwell for fast reloads
  • Integrated Quick Disconnect Points
  • Three Santoprene Rail Panels
  • Full-Latch Impact Plastic Case



About Daniel Defense

Daniel Defense is a family-owned and privately held firearms manufacturer located in Black Creek, Georgia. Founded in 2000 by Marty Daniel, the company was born from Marty’s vision to create custom rifle accessories for his personal rifles. Daniel Defense strives to control every facet of production and makes nearly every component part it sells. When you buy a Daniel Defense product, you’ll get built-in durability, rich feature sets, modularity, great style, and a lifetime satisfaction guarantee. Daniel Defense’s primary offering consists of Rifles, Pistols, Barrels, Uppers, Suppressors, and accessories. MidwayUSA proudly carries many Daniel Defense products, including Semi-Automatic Rifles, Upper Receivers, Barrels, Magazines, Stocks, and more! At Daniel Defense, we celebrate the liberty of our country, the enthusiasm of our Customers and employees, and the quality and accuracy of our products. Daniel Defense – Freedom. Passion. Precision.

Shop Now

Colt M4 Monolithic Carbine Semi-Automatic Centerfire Rifle 5.56x45mm NATO 16.1" Barrel Matte and Black Collapsible

The Colt 6940 monolithic rifle is one of the most popular tactical rifles on the market, and usually one of the hardest to find.  The monlithic design upper is built tough for tactical environments, and shares a common lower receiver with the rest of the M4 and 6920 family of Colt rifles.  The Mil-Spec hammer and trigger pivot pins, a Magpul MBUS backup sight and a folding front sight for enhanced optical solutions, and a straight gas tube and a removable lower rail which provides modularity for under mounting accessories. The patented one-piece monolithic upper receiver incorporates a continuous Mil-Spec rail from the rear of the upper receiver to the front sight. This feature affords unmatched repeatability for mounting optical systems, not found with separate handguard rail systems. Designed with accuracy in mind, its true free-floating barrel provides the enhanced accuracy necessary for long-range acquisition capability.



  • M4 Style Stock
  • Government Profile Barrel
  • Tri-rail

What Customers Are Saying

great product

Just a weekend shooter. Have 500 rounds through it with no problems. used a variety of different ammo all worked well. I use 8 1/2 x 11 paper targets out to 200 yards and never missed yet I use the factory installed sights and never adjusted them the groupings are about 6 inches at 200 yards with the installed factory sights . The fit and finish is very good. The rifle feels robust and I think if you are going to buy a AR rifle just get one of these and call it a day. i have a 38 year old A2 Hbar and a standard M4 this is my go to rifle of choice now and in the future . i liked it so much i bought a monolithic back up upper .. I more than likely will replace the rear sight with something in the future . im not a scope guy and like the point and quick shoot that the iron sights offer. i traded in a A1 for the Hbar . the A1 was the quickest pointing rifle i ever owned.
- none, 4/22/2023

About Colt

Samuel Colt was issued the US Patent for the first Colt Firearm in 1836 and subsequently began constructing his first factory. In 1847 Samuel H. Walker of the US Army collaborated with Colt to develop a more powerful revolver known as the Walker. Colt has been providing quality firearms for the US military throughout history and continues to do so today. Colt is known for its classic revolvers and pistols as well as their semi-automatic rifles and accessories. Their top models, like the Anaconda and Python are legendary guns that are a favorite of many. Today, Colt is a highly sought-after brand for many collectors and firearms enthusiasts around the world.

Shop Now

Bravo Company (BCM) RECCE-14 KMR-A AR-15 Semi-Automatic Centerfire Rifle 5.56x45mm NATO 14.5" Barrel Chrome and Black Battleship Collapsible

The Bravo Company (BCM) RECCE-14 KMR-A AR-15 Semi-Automatic Centerfire Rifle features a 14.5" barrel with a permanently fixed BCM Mod 1 Compensator that extends the length to 16.1" total. The barrel on the BCM RECCE-14 KMR-A AR-15 Rifle is chrome lined and features a mid length gas system, surrounded by BCM's KMR-A13 Free Float KeyMod handguard. The RECCE-14 also features several of BCM's Gunfighter upgrades including the BCM Stock, BCM trigger guard, BCM PNT trigger, and the Gunfighter charging handle. BCM builds professional grade weaponry manufactured, reinforced, and tested to meet the unforgiving needs of professional Soldiers, Law Enforcement, and responsible citizens in some of the most high threat environments in the world.


  • T-Marked Upper Receivers
  • M4 Feed Ramps
  • Independently Certified Mil-Spec 11595E Barrel Steel
  • Chrome Lined Bore and Chamber
  • Manganese Phosphate Barrel Finish on entire barrel
  • Bolt machined from Mil-Spec Carpenter No. 158 steel
  • HPT Bolt (High Pressure Tested/ Proof)
  • MPI Bolt (Magnetic Particle Inspected)
  • Shot Peened Bolt
  • Chrome Lined Carrier (Auto)
  • Chrome Lined Gas Key
  • Gas Key Hardened to USGI Specifications
  • Grade 8 Hardened Fasteners Key
  • Staked Per Mil-Spec
  • Tool Steel Extractor
  • Black Extractor Insert
  • Receivers Machined from Aluminum Forgings 7075-T6
  • Receivers Hardcoat Anodized per MIL-A-8625F, Type III, Class 2
  • Staked M4 Lock Nut
  • USGI H Buffer (1 USGI Tungsten, 2 Steel)
  • Low Shelf for RDIAS installation
  • Low Shelf for Accuwedge use
  • Fire Controls marked Safe and Semi



Shop Now

Ruger AR556 Rifle 5.56x45mm NATO Matte Black Oxide 16" Barrel

The Ruger AR-556 rifle is a gas impingement driven, box magazine fed, autoloading rifle. The mechanism utilizes the gas from the firing of the round to drive the bolt carrier rearward and rotate a bolt that locks into the barrel. The AR-556 rifle can be field stripped without the use of tools and breaks down into basic subassemblies. The safety, located above the trigger on the left side of the lower receiver, blocks the trigger and permits the bolt carrier to be cycled with the safety in the on or “SAFE” position. A bolt catch mechanism is provided for convenience in holding the bolt open for loading and inspection. The firing pin is retracted mechanically as the bolt starts to unlock and the rifle will fire only when the bolt is locked.


What Customers Are Saying

Very satisfied !!

I'm using this as a hog gun. Mounting a 3x gr/red dot by Monstrom. Ruger is always an excellent choice. Should also mention an excellent price as wee as available Ammo. Fast becoming my favorite online shopping destination
- Claycracker2, 4/3/2021

About Ruger

Sturm, Ruger & Co., Inc. is one of the nation's leading manufacturers of rugged, reliable firearms for the commercial sporting market. With products made in America, Ruger offers consumers almost 800 variations of more than 40 product lines across both the Ruger and Marlin brands, such as the American, Mark IV, Vaquero, Blackhawk, Redhawk, and more. Ruger crafts many budget-friendly rifle options as well as replica revolvers and polymer pistols for modern applications. Ruger also produces a selection of gun parts, holsters, and other accessories to complement their firearms. For almost 75 years, Sturm, Ruger & Co., Inc. has been a model of corporate and community responsibility. Our motto, "Arms Makers for Responsible Citizens®," echoes our commitment to these principles as we work hard to deliver quality and innovative firearms.

Shop Now