What is an AR-15?

The AR-15 rifle is light, a semi-automatic rifle that is based upon the design of the Colt AR-15. The original AR-15 rifle was designed as a successor to the AR-10, designed by Eugene Stoner for the Armalite Rifle company. 

The “AR” in AR-15 Rifle stands for “ArmaLite Rifle”. The original AR-15 was a fully automatic, select-fire weapon. Civilian versions of the modern AR-15 are almost exclusively semiautomatic due to weapon regulations in a majority of countries. Meanwhile, the fully automatic version of the AR-15 has been used as the basis of weapon platforms for many militaries around the world.

The History of the AR-15 

AR-15 gun laying on a cloth
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The AR-15 was designed by American gun manufacturer ArmaLite in 1956. The AR-15 was based on the AR-10, an older rifle design also created by ArmaLite. The design of the AR-15 makes use of the 5.56x45mm NATO cartridge, which is smaller and has a higher velocity than the AR-10. This decision allowed soldiers to carry more ammunition while in the field.

The original Colt AR-15 design was for a select-fire rifle that allowed the operator to choose between semi-automatic fire and fully automatic fire. The US military adopted this version of the AR-15 as the M-16 in 1964. A variant of the Colt AR-15 with only semi-automatic fire capabilities is available to civilians today. This variant is simply referred to as the AR-15 rifle.  

What are the Parts of an AR-15?

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The AR-15 is composed of the following parts:

  • Upper receiver: Contains the bolt carrier group and charging handle, which is responsible for loading cartridges into the rifle, firing them, and ejecting spent cartridges.
  • Barrel: Connects to the upper receiver and is the exit from which the shot leaves the weapon. Barrels have internal grooves, called rifling, that impart a spin to the round to provide extra stability.
  • Gas block and gas tube: The AR-15 is a gas-operated rifle. The expanding gasses released by a round being fired are partially channeled back through this system to aid in cycling new rounds into the chamber in the upper receiver.
  • The forward assist: This is a manual button used to help seat an initial round in the chamber upon loading the weapon from empty. 
  • Rail system or handguard: Located along the barrel, a picatinny rail system allows for modular swapping of accessories such as scopes, sights, flashlights, and forward grips. 
  • Lower receiver: considered the core of the firearm, the lower receiver contains the trigger control group. When you pull the trigger, this action activates the firing pin, striking the cartridge and igniting the gunpowder within. This propels the round out of the barrel. 
  • Buttstock: located at the opposite end of the barrel, the buttstock provides stability and improves aim by helping the operator rest the rifle on their shoulder.
  • Magazine: holds the ammunition prior to firing. A loaded magazine fits into the magazine well on the bottom of the lower receiver and provides the supply of ammunition until empty.
  • Pistol grip: attaches to the lower receiver and provides better stability and handling for a rifle. It’s called a pistol grip because it resembles the grip of a handgun.
  • Foregrip: an optional accessory that attaches to the underside of the barrel using the rifle’s rail system. This foregrip is for the forward non-trigger hand of the operator and aids in aiming and provides better stability

What Caliber are AR-15 Rifles?

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The original caliber of the AR-15 rifle is 5.56x45mm. This caliber is also referred to as 5.56 NATO and is the most popular caliber because it complies with NATO standards. While AR-15 rifles can be chambered in different calibers, these tend not to be as popular as 5.56 NATO. Some AR-15s can take .223 Remington cartridges, a caliber usually seen in hunting rifles, as these two calibers are nearly identical. 

Unlike 5.56 NATO, .223 Remington fires at a much lower pressure of approximately 55,000 PSI. This is much less than the up to 65,000 PSI of force that a 5.56 NATO round creates upon firing. Firing a 5.56 NATO round in an AR-15 that is only designed to withstand the pressures of a .223 cartridge can present a safety hazard. Always confirm that you are using the right ammunition designed for your AR-15.

What Capacity are AR-15 Rifles?

AR-15 Magazine

The AR-15 rifle uses a magazine system that has a standard capacity of either 20 or 30 rounds. Some states such as New York and California require the use of smaller capacity magazines, usually limiting the AR-15 to only 5 or 10 rounds. 

How much do AR-15s Cost?

The cost of a typical AR-15 rifle varies from $500 to over $2000. The AR-15 cost is impacted by the metals and plastic compounds used by the manufacturer, build quality, wear control coatings, and weight of the components used. 

Here’s a list of other AR-15 rifle upgrades that can increase the total cost. 

AR15 triggers
Attribution: 80percentarms.com
  • Modifying the lower receiver to accommodate left-handed shooters
  • Adding better optics for increased accuracy
  • Adding a longer or floating barrels
  • Using complex or adjustable stocks
  • Adding bipods

How Well do AR-15 Rifles Hold their Value?

A used AR-15 rifle is generally worth 60% to 80% of its original price. How well an AR-15 rifle holds its value depends on how much it’s been used and how well it has been maintained. The age of the rifle has less of an impact on the resale value. 

How much do AR-15s Weigh?

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A typical AR-15 weighs around 6.5 lbs empty. A fully loaded AR-15 with a 30-round magazine weighs 7.5 lbs. The weight of the AR-15 rifle is most impacted by the barrel, bolt carrier group, and buttstock. Adding a magnified scope can also increase the weight of an AR-15 by 1-2 lbs.

How Long are AR-15 Rifles?

The length of an AR-15 rifle is between 36 inches and 44 inches long. A standard AR-15 rifle with a 20-inch barrel is approximately 40 inches long. There are shorter variants with 16-inch barrels as well as longer variants with 24-inch barrels. 

AR 15 gun vertically captured on a cut tree
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An AR-15 carbine will typically have a barrel length of between 10 and 18 inches, which will result in an overall length of 30 to 38 inches long. AR-15 pistols have much shorter barrels and the overall length of an AR-15 pistol can be as short as 27 inches long. 

What Thread Pattern do AR-15 Rifles use?

The AR-15 uses a 1/2×28 thread pitch. This is standard for rifles chambered in 5.56 NATO. 

Who Manufactures AR-15 Rifles?

Place for gun making
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AR-15 rifles are made by the following 18 manufacturers:

  • Aero Precision: Founded in 1994, Aero Precision specializes in AR-15 rifles and both upper and lower receivers. They also sell scope mounts, barrels, and other products
  • Bravo Company Manufacturing: A veteran-owned company that started in 2005. They specialize in building rifles to military specifications. 
  • Colt: Colt produces civilian versions of the rifle that are as close as you can legally get to a military M4. They are one of the original manufacturers of the AR-15, 
  • CMMG: Founded in 2002 by John and Jeff Overstreet, CMMG initially created AR-15 upper and lower receivers but has been marketing complete rifles since 2005.
  • Daniel Defense: Daniel Defense was founded by Marty Daniel when he found a lack of high-quality parts for his M16. They are one of only five companies worldwide that make cold hammer-forged barrels. 
  • FN Herstal: A Belgian arms manufacturer that also owns Browning and Winchester, two well-known American rifle manufacturers. FN Herstal markets AR-15 rifles under the FN-15 trademark.
  • Geissele: Pronounced “guys-lee”, Giessele was founded in 2008 in Pennsylvania. Geissele also develops select-fire trigger groups for the US armed forces. They were originally a manufacturer of civilian trigger groups, 
  • Knight’s Armament: Famous for employing Eugene Stoner, the original designer of the AR-15 until his death, Knight’s Armament has been iterating on the AR-15 for 30 years.
  • LaRue Tactical
  • Lewis Machine and Tool (LMT): Founded in 1980, LMT is most known for President Karl Lewis’ Monolithic Rail Platform, which is a one-piece mil-spec upper receiver with an integral forend.
  • LWRC: Acquired by Pat Bryan in 2006, LWRC has since gone on to develop a patented short-stroke gas piston system for the AR-15 that meets U.S. Army Individual Carbine program requirements.
  • Noveske: Founded by the late John Noveske in 2001 after returning home from serving in the U.S. Army. 
  • Palmetto State Armory: Based in South Carolina, known as “The Palmetto State”, this weapons manufacturer sells firearms, tactical equipment, reloading supplies, as well as fishing and hunting equipment.
  • POF: POF is short for “Patriot Ordnance Factory”. POF was founded in 2002 by American aerospace engineer Frank DeSomma to solve carbon fouling and short-barreled timing issues with the AR-15.
  • Rock River: Rock River Arms was founded in 1996 and is owned and operated by Mark and Chuck Larson. They originally produced custom Colt 1911 semiautomatic pistols before also beginning to manufacture AR-15s.
  • Ruger: Founded in 1949 by Bill Ruger and Alex Sturm, Ruger is one of the largest firearm manufacturers in the United States. Ruger produces bolt-action, semi-automatic, and single-shot rifles, shotguns, semi-automatic pistols, and single- and double-action revolvers.
  • SIG Sauer: Originally formed in 1976 in Europe, the American branch of SIG Sauer introduced the SIG516 AR-style rifle in 2010. This was discontinued in 2019 but SIG Sauer still sells AR-style rifles chambered in different calibers.
  • S&W: Smith & Wesson was founded in 1856 with a long pedigree, this arms manufacturer produces the M&P15 series of AR-15 rifles. 

Where can you buy an AR-15 rifle?

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You can buy an AR-15 rifle from a licensed gun store or private seller at a gun show. It’s also possible to purchase an AR-15 rifle online but it can only be picked up from a local gun store or Federal Firearm Licensee (FFL). Picking up the AR-15 rifle at a FFL solves the background check requirement which is required to purchase a firearm.

In some states such as Texas, you can leave the store with your AR-15 the same day. In other states such as California, you may be subject to a waiting period as short as 24 hours or as long as 10 days.

Are AR-15’s Legal?

AR-15 rifles are legal in 18 countries. The table below shows where AR-15 rifles are legal:

United StatesEach state in the union is permitted to regulate firearms as they see fit. The result of this is that there are many states that have differing AR-15 regulations.
CanadaOn May 1, 2020, the Government of Canada has prohibited AR-15 rifles. Upper receivers of AR-15 pattern firearms are also prohibited.
MexicoTitle II, Chapter I, Article 9 of the Federal Law of Firearms and Explosives states that semi-automatic rifles chambered in .223 caliber are illegal in Mexico.
United KingdomSemi-automatic rifles are limited to .22 caliber in the UK.
RussiaAs of 2013 Russian citizens over 18 years of age can obtain a firearms license after attending gun-safety classes and passing a federal test and background check. Firearms may be acquired for self-defense, hunting, or sports activities, as well as for collection purposes.
Chinaaccess by the general public to firearms is subject to some of the strictest control measures in the world. With the exception of individuals with hunting permits and some ethnic minorities, civilian firearm ownership is restricted to non-individual entities
AustraliaAll self-loading centrefire rifles, pump-action or self-loading or lever-action shotguns that have a magazine capacity of more than 5 rounds, and semi-automatic rimfire rifles over 10 rounds, are restricted to government agencies, occupational shooters and primary producers.
JapanThe Swords and Firearms Possession Control Law of Japan states that “No one shall possess a firearm or firearms or a sword or sword” with only a few exceptions. 
The PhilippinesThe Comprehensive Firearms and Ammunition Regulation Act of the Philippines classifies the AR-15 as legal following owner certification.
PakistanAs one of the most permissive nations on the planet when it comes to gun control, Pakistan permits AR-15 ownership. Even automatic weapons are permitted in Pakistan.
ArgentinaSsemi-automatic rifles above .22 caliber, and long rifles with detachable magazines are prohibited in Argentina.
BrazilThere are few to no restrictions on firearms in Brazil besides being 25 years of age or older, though it is illegal to carry a gun outside of your residence.
IndiaThe Indian Arms Act of 1959 classifies semi-automatic rifles like the AR-15 as “prohibited bore” firearms.
IsraelIsraeli citizens are limited to the ownership of one firearm at a time, specifically handguns. Access to AR-15 rifles is limited to shooting clubs and the military.
South KoreaAll firearms in South Korea are strictly regulated, usually only available to military or law enforcement personnel.
United Arab EmiratesPossessing firearms in the UAE is legal as long as they are registered. Only UAE residents may own firearms.
New ZealandAs of late 2019, all semi-auto center-fire rifles and any rifle or rifle magazine capable of holding more than 10 rounds are restricted by New Zealand law.

What Part Of An AR 15 Rifle Is Registered?

standard stripped lower receiver
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The lower receiver of the AR 15 rifle is registered. The lower receiver contains the fire control group and bears the serial number, the name of the manufacturer, and other important details.

How Old Do You Have To Be To Buy An AR-15 Rifle?

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The minimum age to buy an AR-15 rifle in the United States is 18 years old. Some states, such as Hawaii and Illinois, have raised this minimum age to 21.

How Accurate is an AR-15 Rifle?

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The AR-15 rifle is an accurate rifle capable of shooting 5 shot groups of around 1.5 Minute of Angle (MOA). This is equivalent to shooting a group of shots with a 1.5″ diameter at a distance of 100 yards.

How Fast Does an AR-15 Rifle Shoot?

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A fully-automatic AR-15 rifle can shoot 700 to 800 rounds per minute. Limitations to this rate of fire are due to risks of the barrel overheating while under continuous fire. 

Upgrading the barrel of a fully-automatic AR-15 can increase the rate of fire to as high as 900 rounds per minute. Semi-automatic AR-15 rifles have a rate of fire of approximately 45 rounds per minute. The semi-automatic AR-15 firing rate is limited to how fast you can pull the trigger as each trigger pull is one shot.

How Loud is an AR-15?

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AR-15 rifle fire shoots at around 155 to 165 decibels. This is loud enough to damage your hearing without wearing ear protection. The volume of an AR-15 shot can further be reduced through the use of suppressors, accessories that can be threaded to the muzzle of the barrel and act to dampen the sound of a gunshot. Suppressors are not available in all US states, as some state governments such as California, Hawaii, and New York have chosen to restrict their use.

How does an AR-15 Work

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The AR-15 is a magazine-fed, gas-powered semi-automatic rifle that fires a round every time you pull the trigger. The AR-15 operates as follows:

  1. The operator pulls the trigger which causes the firing pin to ignite the gunpowder in the rifle cartridge. 
  2. The hot gasses from the explosion propel the bullet through the barrel and towards the target. 
  3. A portion of the gasses are diverted to rotate the chamber and eject the now-spent rifle cartridge. This action compresses the recoil spring.
  4. When the gasses dissipate, this spring returns the bolt to its original position, stripping a new cartridge from the magazine and setting it in place inside the firing mechanism. 
  5. This cycle then repeats with every pull of the trigger.

Why are AR-15 Rifles so Popular

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AR-15 rifles are popular because they are very modularized, light, accurate, versatile, widely available, and relatively inexpensive. There are also many different accessories and aftermarket parts for the AR-15 that make it easy to customize the rifle. 

In 2021, ABC News reported that the United States had over 20 million AR-15-style rifles legally in circulation. Common AR-15 Use Cases

AR-15s have the following uses:

AR-15 Rifles for Hunting

The AR-15 rifle is popular for hunting because of its light weight and its high accuracy at long range. AR-15 rifles used for hunting have longer barrels for even more accuracy and are often equipped with a high-powered scope.

Photo Credit: Unsplash

AR-15 Rifles for Home Defense

The AR-15 rifle is also popular for home defense because of its relative stopping power, light weight, ease of use, and high availability of ammunition.  

AR-15 Rifles for Militaries

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The AR-15 rifle has never been used by the United States Military, or any other military in the world.. Instead, the United States military uses the fully automatic, military-grade form of the AR-15 known as the M16. The M16 is currently in use by the militaries of 15 NATO countries and more than 80 countries worldwide such as the Philippines, Canada, and Afghanistan.

AR-15 Rifles for Police Officers

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AR-15 rifles are occasionally used by law enforcement officers who have completed special training. Officers who are rifle-qualified have to demonstrate proficiency with the rifles at least once per year.

While on duty, the AR-15 rifle is carried inside the car in a locked rack either alongside or in place of the shotgun. The AR-15 rifle may also be locked in the vehicle trunk or in a separate weapon compartment (in the case of a SUV-type patrol vehicle). Some officers also carry a sling bag they can drape over their shoulder quickly, loaded with spare magazines for the AR-15 rifle.

AR-15 Rifle Alternatives

The popular alternatives to the AR-15 rifle are as follows:

CaliberOverall LengthWeight
M162.23/5.56 NATO34 to 42 inches6-8 lbs
M42.23/5.56 NATO29-33 inches6.5-7.5 lbs
AR-15 Pistol2.23/5.56 NATO26 inches5-7 lbs
AR-107.62×51 NATO41 inches8-10 lbs
AK-477.62x39mm35 inches8-9.5 lbs
Mini 142.23/5.56 NATO37 inches 6.5-7.5 lbs

What are the differences between an AR-15 and M16?

Is the AR-15 the Same as an M-16
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The M16 is virtually identical to the AR-15. Unlike the AR-15 rifle, the M16 is a select-fire weapon capable of automatic fire whereas the AR-15 is only capable of semiautomatic fire. The M-16 is generally not available for civilian use and is reserved for military applications.

What are the differences between an AR-15 and M4?

The M4 is based on the AR-15 platform and is a select-fire variant that is only available to military forces. Unlike the AR-15 which has an average barrel length of 16 to 24 inches, the M4 is a carbine with a shorter barrel of 14.5 inches. The M4 lacks a carry handle and usually has a collapsible stock.

​AR15 vs M16 vs M4: What’s the Difference? thumbnail image
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What are the differences between an AR-15 Rifle and AR-15 Pistol

Should You Choose an AR-15 Rifle or Pistol? | OutdoorHub
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An AR-15 pistol is chambered for the same ammunition type as the AR-15 rifle. Unlike the AR-15 rifle, the AR-15 pistol has a shorter overall length of just 26 inches, no vertical forward grip, and no buttstock. Because the AR-15 pistol is smaller than the AR-15 rifle, there is less space for accessories like foregrips.

What are the differences between an AR-15 and AR-10?

An AR-10 (above) and AR-15 (below). (Image courtesy of YouTube)
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The AR-10 and the AR-15 were both designed by Armalite. The AR-15 rifle was designed in the 1960s, around ten years after the AR-10 was designed. 

Unlike the AR-15 rifle, the AR-10 is chambered for 7.62×51mm ammunition. The AR-10 is larger and heavier than the AR-15 rifle, measuring 41 inches in length and weighing 8-10 pounds. The AR-10 also has a slightly longer effective range of 600 meters and a slower firing rate of 700 rounds per minute. 

What are the differences between an AR-15 Rifle and AK-47?

Choosing between the AR-15 and the AK-47
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Unlike the AR-15 rifle which is American-designed, the AK-47 is a Russian design created by Soviet general Mikhail Kalashnikov in 1947. The AR-15 is chambered for 5.56x45mm, but the AK-47 is chambered for 7.62x39mm. 

The AR-15 is more accurate than the AK-47 at longer ranges, with the effective range of an AK-47 closer to 380 yards compared to the AR-15’s 500 yards. The AR-15 rifle is also lighter than the AK-47 by 1 to 2 pounds.

The semi-automatic version of the AK-47 cost on average $500 and $800, making it slightly less expensive than a semi-automatic AR-15 rifle.

What are the differences between an AR-15 and Mini 14?

Mini-14 is better than the AR-15
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The AR-15 and the Mini 14 are both semi automatic rifles. The Mini 14 is based on the M-14 (also known as the M1A Garand). Both AR-15 and Mini 14 are typically chambered for 5.56x45mm, the NATO standard. 

Unlike the AR-15 rifle that is available from multiple manufacturers, the Mini 14 is exclusively made and sold by Ruger. Servicing or upgrading an AR-15 is easier than servicing a Mini 14 since parts are made by any one of the 18 US manufacturers of AR platform firearms. The Mini 14 is severely limited as you can only purchase parts from a single company.