By Will Dabbs

The term AR-15 has taken on near-supernatural significance this deep into the Information Age. America’s rifle is either hero or villain depending upon political bent. While the terms AR-15 and AR-10 are bandied about regularly in the popular media, it behooves us to know the actual similarities and differences between each. So, what are the differences when you put the AR-10 vs. AR-15?

There are literally tens of millions in circulation. A typical example is around 36-inches long. If you took all of the AR-pattern rifles in America and placed them muzzle to butt they would stretch from New York City to Los Angeles and back, twice. That’s a whole lot of guns.

“AR-15” has evolved into a generic term of sorts. AR stands for ArmaLite Rifle in homage to the gun’s origins. While they can now be found in calibers ranging from .22 LR up through .50 BMG, most run 5.56x45mm. Everyone knows what they look like. But what is an AR-10 exactly?

Think of your typical AR-10 rifle as an AR-15 on steroids. These guns feature a slightly larger receiver set and associated particulars so they can manage heavier calibers. While they can also be found in lots of different chamberings, most of them run .308 (AKA 7.62x51mm). The AR-10 actually came first.

The Current Lay of the Land

When you put the AR-10 vs. AR-15, they fill two similar but different roles. The lighter AR-15 is optimized for home defense, competition and recreational shooting. The larger-caliber AR-10 renders better service as a precision long-range platform or for hunting moderate-sized North American game, such as deer. 

There are literally countless variations, and they can all be found on GunBroker. A basic no-frills 5.56mm AR-15 can be had for around $500, sometimes substantially less. A comparable AR-10 in .308 will be a c-note or two more. 

On the other end of the spectrum, you will find rarefied versions with all the bells and whistles. The HK piston-driven examples can run six grand or so. Ballistic happiness can be found anyplace between those two extremes.

Origin Story

First introduced in 1956, the AR-10 rifle represented an effort to incorporate the extraordinary advances in materials science that defined WW II aviation into modern small arms. The AR-10 was indeed a radically advanced design. At the time, its 7.62x51mm cartridge was the brand new replacement for the venerable .30-06 that carried us through both World Wars. 

That early AR-10 was the product of a tiny little brain trust called ArmaLite. ArmaLite was a subset of the Fairchild Engine and Aircraft Company, a fairly massive aerospace manufacturing concern. Gene Stoner was the chief engineer. He was the 9th employee of the company.

ArmaLite was not set up to mass produce guns. Their business model orbited around perfecting these designs and then farming production out to established gun companies. There was a precedent for this. When John Taliaferro Thompson designed his eponymous Thompson submachine gun back in the early 1920s, he contracted with Colt’s Manufacturing to actually build them.

The AR-10 featured an advanced straight-line design that helped mitigate recoil and muzzle rise along with upper and lower receivers cut from aircraft-grade aluminum. It also included phenolic polymer furniture, something that was essentially unheard of at the time. The selective-fire AR-10 fed from a detachable 20-round box magazine. 

ArmaLite wanted to enter their AR-10 into the military competition that ultimately selected the M14 service rifle. At that time, however, the AR-10 design was not yet fully mature. The barrel of those earliest rifles was composed of a steel sleeve nestled inside of an aluminum cylinder. One of these rigs exploded during testing, and the AR-10 was disqualified.

The ArmaLite folks fixed those problems and eventually farmed out production to Artillerie-Inrichtingen, a Dutch gun company. Portugal bought a bunch of these rifles and used them in their sundry African bushfire wars in an unsuccessful bid to hang onto their colonial conquests.

Some Shrinkage May Occur

In 1957, Stoner and Company took the basic AR-10 action and shrunk it down to accommodate the then-revolutionary .223 cartridge. The .223 was an evolutionary development of the previous .222, also a Gene Stoner design. The resulting rifle was unnaturally lightweight and maneuverable. It also looked like something out of a Buck Rogers science fiction serial. 

Malaya was actually the first nation to buy a few. Then, U.S. Air Force General Curtis LeMay had opportunity to blow a few pumpkins to bits with an AR-15 at a holiday picnic and was smitten with the trim little rifle. He got a bunch for the Air Force, and the Army subsequently jumped onto that bandwagon as well. The Big Green Machine rechristened the weapon the M16, and the rest is history. The design evolved considerably over time, but now these civilian-variant semiautomatic AR-15 rifles are absolutely everywhere.

Variety is the Spice of Life

There are also pistol versions of both the AR-15 and AR-10. Adding a pistol-stabilizing brace gets you most of the functionality of the parent rifle in a markedly smaller package. Uncle Sam has been a bit bipolar about pistol braces in years past, but they seem to be here to stay now.

Pistol-caliber AR-15 rifles and pistols bring a whole new dimension to your range experience. Firing common and relatively inexpensive 9mm and .45ACP, these guns sport the same ergonomics and modularity of their rifle-caliber counterparts without the recoil and muzzle blast. Selecting the right gun with the right cool-guy stuff to suit your mission, your personality, and your budget is half the fun.

Ruminations of AR-10 vs. AR-15

If you want something you can secure behind the seat in your minivan, then an AR-15 pistol would likely be a good fit. Those who might also use the gun for home defense, competition and general fun at the range, then a full-size AR-15 rifle is probably your go-to iron. If you want to reach out a ways or if the threat might be hiding behind something substantial, then a .308 AR-10 brings that extra horsepower. The latter option will also reliably put venison on your table. Regardless of what you’re looking for, GunBroker is one-stop shopping for anything that shoots.

Tags: AR 10, AR 15, Colt, COLT M16, Semi Auto Rifles