What is an AR-15?



Image via Colt

I was enjoying a novel the other day until a character switched an AR-15 (pictured above) into fully automatic mode and started blasting away at bad guys. Thing is, AR-15s don’t have a full-auto mode. It’s time to clear the waters, because this is only one of the misconceptions.

AR-15s Are…

  • Semi-automatic rifles – Pull the trigger once and the rifle will shoot one time. There are no fire modes to switch in and out of, that’s all it does. Fully automatic is different from semi-automatic in that one pull of the trigger can equal multiple shots fired consecutively.
  • Both a model and a type – This seems tricky, but it’s not too confusing. Colt is the only company that can say it makes a genuine AR-15 (the model). However, other companies make AR-15 clones and AR 15 accessories and put their own spin on them. In both cases, you could write AR-15 (or just AR) and still be accurate.
  • Customizable – AR-15s come ready to attach any number of accessories, which is part of the reason they’re popular.
  • Old – For as recent as AR-15s seem, Eugene Stoner actually designed the first one in the 1950s. The .223 caliber ammunition most often used in AR-15s (there are others) is also nothing new.

AR-15s Are Not…

  • Assault rifles – The “AR” stands for Armalite Rifle, not assault rifle. An assault rifle is capable of switching between different modes of fire, such as semi-automatic and fully automatic. The AR-15 can’t do that, it’s stuck in semi-auto mode.
  • Capable of using clips – AR-15s use magazines, not clips.

Why the Confusion? Blame the M16

The AR-15 shares a common lineage with the M16, the iconic U.S. military rifle in use since the 1960s. They both look similar, but appearances are often deceiving when it comes to firearms. The M16 can switch between modes of fire, from semi-auto to full-auto and back again. This is an M16 (image via Shutterstock).


In the case of the book I was reading, this is where the author tripped up. The character’s firearm was called an AR-15, but functioned like an M16. The author in this case should’ve picked one and stuck with it, although the AR-15 is the more likely choice given the civilian character’s circumstance. M16s are hard to come by outside of the military.

Get the Book

The Writers Guide to WeaponsThe Writer’s Guide to Weapons: A Practical Reference for Using Firearms and Knives in Fiction (Writer’s Digest Books) comes with everything but the ammo. Pick up a print or digital copy from these fine retailers:

6 thoughts on “What is an AR-15?

  1. A friend bought one of these ‘cause he said the gun dealer told him he couldn’t sell him an M-16, and these are used by the Canadian Forces.

    Looks like he was mostly right – they actually use the Colt Canada C7 rifle, which is a variant of the AR-15.

    All I can tell you for sure is an AR-15 is a weapon that can assault anyone in sight by the sound alone.

    Liked by 1 person

    • Thanks, Steve. From what I can tell, the M-16 and the C7 are identical, except for the naming conventions of the U.S. and Canadian militaries. And you wouldn’t be able to buy an M-16 in the States, either, since they can fire in a fully automatic mode. No U.S. civilian can buy any full auto made after May 19, 1986.

      AR-15s are still popular here, though, mostly for shooting sports and hunting. They’re more for enthusiasts than self-defense, not all that different from run-of-the-mill .223 rifles.


  2. When I went through U S. Army BASIC training in 1988 and we had COLT AR-15 rifles. They fired in both semi and full auto modes. ( AR-15 not M-16 was on the weapons.) Just saying.

    Liked by 1 person

  3. Things are convoluted because “AR-15” is a trademarked name that has been applied to distinct but similar models of firearm. When ArmaLite (then a subsidiary of Fairchild, an aircraft builder) developed the AR-15 in the late 1950s, it was a selective fire weapon (i.e. an assault rifle) and the US government purchased a number under that name. They weren’t exclusively used by the armed forces; some civilian advisors in Vietnam kept them in their cars in case they encountered a VC ambush.

    The armed forces adopted what was then the AR-15 under the designation M16. Around that time, Fairchild decided to get out of manufacturing firearms, and the intellectual property was sold to Colt, including the name “AR-15.” Colt made the assault rifle under the name “M16” but developed a semi-auto-only version, to which it applied the name “AR-15.” These came on the market in 1965. So an important distinction is whether the weapon under discussion is an ArmaLite AR-15 (made before before 1965 and capable of automatic fire) or a Colt AR-15 (made from 1965 onwards and not capable of automatic fire). Or it could be a generic “AR-15,” made by a third manufacturer after the patents (but not the trademark) expired in the 1970s, also semi-auto-only.

    My point being that it’s not entirely impossible for a character to have an AR-15 capable of automatic fire, provided it’s a pre-1965 ArmaLite model. It’s very unlikely, of course, as not many were made and very few made their way into civilian hands; the story of how the character came by such a rifle might well be more interesting that the story he’s using it in.


    • I was an Australian soldier in Vietnam in 1969-70 and we were using weapons engraved Colt AR15 and had selective auto full auto fire options. We called them Armalites or M16s. M16 was the military terminology.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s