What Does AR Stand For in AR15? ArmaLite Rifle Meaning

AR stands for ArmaLite Rifle. ArmaLite is the company that designed the rifle in the 1950s. The 15 is ArmaLite's model number in the company's sequence of rifle designs from that decade of rifle design. AR does not mean assault rifle, and it does not mean automatic rifle, either one of those names.

I am Matt Rice, and I founded Ozark Armament in 2016. I run the company from Tigard, Oregon, and I have personally zeroed hundreds of rifles across iron sights, red dots, lasers and optics.

What does the AR in AR-15 stand for?

Those letters AR stand for ArmaLite Rifle, and ArmaLite is the company that designed and named the rifles carrying that prefix. The archived wording on ArmaLite's own history page says, "All rifles were designated AR, short for Armalite Rifle," and that line defines AR as the company name. Bear Creek Arsenal, a retailer, says the letters stand for ArmaLite Rifle and not for assault rifle or automatic rifle. Shop Black Rifle, a second retailer, gives that same definition, ArmaLite Rifle and not assault rifle or automatic rifle. In technical use, an assault rifle is a select-fire rifle, meaning it can fire in more than one mode rather than in one mode only. The select-fire definition is neutral background for the word assault, kept beside the company prefix on the rifle and not used as a second name for the letters.

Customers ask me what "AR" means about a few times a week at the shop; most guess assault rifle.

When customers ask, I still say it out loud: AR is ArmaLite Rifle, not assault rifle; that's the company that designed the platform in the late 1950s before Colt took the license.

On our catalog ARs I walk new shooters through the naming once so the acronym doesn't keep derailing the safety brief.

What does the 15 mean in AR-15?

The 15 in AR-15 is a model number. ArmaLite numbered its rifle designs in a model sequence, and ArmaLite's history page says work on the AR-1 "Parasniper" began in the early 1950s, early in that model sequence. ArmaLite then submitted the AR-5, a .22 Hornet survival rifle, to the U.S. Air Force, and the Air Force adopted that survival rifle as the MA-1 Survival Rifle. ArmaLite's first commercial rifle was the AR-7 Explorer, the civilian version of the AR-5. The same page records the AR-10 as the larger rifle that came before the AR-15, and it lists the later AR-18 as well. In 1956 Army officials asked ArmaLite to develop a smaller version of the AR-10 as a potential replacement for the M1 Garand. That request from the Army produced the rifle called the AR-15, drawn as a smaller rifle from the AR-10. ArmaLite's page gives that rifle aircraft grade aluminum receivers and a weight under seven pounds for the rifle. That number says nothing about caliber, nothing about capacity, and nothing about how the rifle works.

Illustration (AI-generated) of five text labels on an AI-generated backdrop, not a photo.

Where did the AR-15 come from?

American Rifleman's "The ArmaLite Story" starts with George Sullivan, patent counsel for Lockheed Aircraft Corporation, a visionary and a firearm enthusiast in the aircraft business. Richard Boutelle, president of Fairchild Aircraft, was intrigued by Sullivan's ideas and in the early 1950s provided funding for a foray into designing small arms. Sullivan set up shop in a small building in Hollywood, California, a shop affectionately called "George's Backyard Garage". The plan was to use ideas from the aircraft industry to create radical new designs for small arms, build prototypes of those designs in the shop and market them to manufacturers who would produce them under license. On October 1, 1954, ArmaLite became a division of Fairchild Aircraft, and ArmaLite's own page names the parent company Fairchild Engine and Airplane Corporation.

Eugene Stoner guided the work at ArmaLite, with the AR-10 as the main focus. American Rifleman's ArmaLite story says the AR-10 arrived too late to win the military trials, so the contract went to the T44, adopted as the M14. In early 1959 ArmaLite licensed the rights to both the AR-10 and the AR-15 to Colt's Manufacturing for $75,000 and a 4.5 percent royalty. ArmaLite's history page says that in 1959 the AR-10 was licensed to the Dutch arsenal Artillerie Inrichtingen for sale on the international market, and then to Colt along with the AR-15. At Richard Boutelle's birthday party in Maryland, Bobby MacDonald, one of the Colt's representatives, handed Air Force General Curtis LeMay an AR-15 and let him shoot a couple of watermelons. LeMay quickly requested AR-15s to replace M1 Carbines for the Air Force personnel who secured Strategic Air Command bases. In Vietnam the rifle became a general-issue arm and then the standard-issue U.S. service rifle, supplanting the M14, under the military designation M16.

How is an AR-15 different from an M16?

Shop Black Rifle, a retailer, describes the AR-15 as a lightweight semi-automatic rifle with a detachable magazine, and describes the M16 that Colt built for the U.S. military, after Eugene Stoner developed the design at ArmaLite, ArmaLite sold it to Colt, and Colt redesigned and modified it, as the standard-issue automatic rifle for U.S. soldiers during the Vietnam War. American Rifleman reports the AR-15 was subsequently given the military designation M16. Many of the early problems on that rifle came from adopting the new rifle without adequate testing or without adequate training. Colt's, with Eugene Stoner as a consultant on the work, eventually corrected the serious problems on the rifle, especially the extraction problems and the jamming.

Functionally it's a gas-operated semi-auto that feeds from a detachable magazine; the letters don't describe the fire control.

ArmaLite called the design the AR-15 after the 1956 Army request, and the military gave the same rifle the M16 name.

Why does every maker say AR stands for ArmaLite on an AR-15?

ArmaLite faced the problem that the AR-15 patents had passed to Colt's, so the company, in American Rifleman's "The ArmaLite Story", created the AR-18, a low-cost .223 rifle made from stampings with a different gas system. Following the expiration of Stoner's patents, Eagle Arms made rifles of the AR-15 type and parts of the AR-15 type. The AR-18 was the rifle ArmaLite itself built while those patents were at Colt's, and the Eagle Arms rifles and parts came after Stoner's patents had expired. Mark Westrom bought Eagle Arms, the firm that made those rifles and those parts. He then bought the ArmaLite trademark as well, after buying the firm.

Readers who want the legal side of owning the rifle can read AR-15 laws by state in the state guide Ozark Armament offers.

What does the AR-15 name mean when you shop for parts?

Because AR-15 names a platform and not one company's rifle, the parts you put on it and the optics you put on it come from many makers, so you compare the makers before you buy a sight or an optic for the rifle you are outfitting. A sight for that platform and an optic for that platform can come from different makers, and the rifle name alone will not sort those makers for you. You take the coverage period, the return window, and who stands behind the part in the same comparison. Ozark Armament is a Tigard, Oregon company that sells optics and sights for the AR-15 platform you are shopping. Its products carry the No B.S. Lifetime Warranty against manufacturing defects, and that warranty is the coverage period on the products. The store has a 30 day return policy for products in good condition.

Listed as of October 2026, the carry handle rear sight is $29.99 on sale, down from $49.99, with 4.7 stars from 780 reviews on the product page. The sight is all aluminum. Adjustment covers windage and elevation, and the clicks are A2 clicks. Two apertures sit on it, a small aperture meant for long range and a large aperture meant for short range and for low light. You mount it on any standard Picatinny rail on the rifle, and thumbscrews handle both the install and the removal. A verified Ozark Armament buyer of the carry handle rear sight wrote about the fit, "Fit fine and dandy. Reminds me of my old M16 I carried in basic training many years ago." Another verified buyer put the same sight this way, "Carry handle is functional. Not perfect, cosmetically, but functions 100% as intended."

A third verified buyer of the carry handle rear sight wrote a note on the flip of the dual aperture and on the size of the rail knobs, "It does it's purpose wish the dual aperture was a little easier to flip and that the knobs to tighten the sight to the rail were a little smaller." That note is one buyer's view of that one sight only, not a description of every unit, and the words name a dual aperture harder to flip than that buyer wished and rail knobs larger than that buyer wished.

Read what the numbers on a scope mean when you want the guide that explains what the numbers on a scope mean, so the figures on the scope have a plain reading you can follow when those figures come up on the scope you are holding and you need to know what each figure names. Open AR-15 scopes when you want the page that collects the scopes Ozark Armament sells for the platform.

Choose the height of a mount with the guide to scope mount height for choosing the height of a mount on the rifle you are setting up at the bench. Take the guide on how to bore sight a scope as a step before live fire.

Ozark Armament catalog photo of the Rhino 4x Magnified Optic, an example of a magnified optic, not a range photo.

Get your AR on paper. Free.

Print free printable sight-in targets when you need paper targets for a sight-in session you can take to the bench with the rifle and the optic you are zeroing. Ozark Armament offers that paper free of charge for the session you are running. Run the zero calculator to work out a zero you can use at the bench for the optic you are putting on the rifle that day, in the same sight-in session.

Frequently Asked Questions

Q: What type of gun is an AR-15?

A: Shop Black Rifle, a retailer, says today an AR-15 is used for hunting and target shooting. The same retailer says AR-15s are nominally chambered in .223 or 5.56mm NATO, and that manufacturers also produce variants in .22 LR, 300 Blackout, 7.62x39mm and 6.5 Grendel.

Q: What does AR-17 stand for?

A: AR stands for ArmaLite Rifle, the same prefix the company used on the AR-15. ArmaLite's history page lists the AR-17 as a 12-gauge shotgun, one of the company's designs. A shotgun on that list puts the letters on the company, and the prefix is not a firing mode.

Q: Is an AR-15 the same as a 223?

A: No. Shop Black Rifle, a retailer, says AR-15s are nominally chambered in .223 or 5.56mm NATO. In that description, .223 is the cartridge the rifle is chambered for, and 5.56mm NATO is the other nominal chambering the retailer lists beside it. AR-15 is the name of the platform, not another word for the .223 cartridge.

Q: What does M16 stand for?

A: M16 is a military service name, and it is not an ArmaLite model number from the company's design list. American Rifleman says that in Vietnam, American personnel noted that the light, fast-handling gun was better suited to jungle warfare than any other battle rifle-caliber longarm available.

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ARTICLE WRITTEN BY MATT RICE, OWNER OF OZARK ARMAMENT