AR10 VS AR15 – Know The Difference Between Armalite Rifles

AR10 vs AR15

Not many people know that one of the most popular and talked-about rifles in the United States, the AR-15, was derived from the original AR-10, originally designed in the 1950s. Both rifles are the brainchild of celebrated gun designer Eugene Stoner. AR stands for ArmaLite, which later sold the designs for both guns to the Colt Manufacturing Company in 1959.

Here, we will give you a quick explanation of what a rifle is, study both the rifles individually and then make a comparison of both the guns.

What Is A Rifle?

Quite simply, a gun fired from shoulder level, with spiral grooves in the barrel to make the bullet spin and as a result, have more accuracy over a large distance is a rifle. Rifles became more popular during the World War 1, simply because of their reliability, greater range and maneuverability, and the ease of use.

Now that we have a basic idea of what a rifle is, we will move on to what exactly is an AR-10 or AR-15.

How The AR-10 Came Into Being


Originally known as the “para-sniper”, the AR-10 (by the Fairchild Aircraft Company) was designed to be a lightweight, shorter than a traditional rifle, and easy to jump out with from say, an aeroplane in the early 1950s. The subdivision that manufactured the rifle became known as ArmaLite. But the company ran into trouble with funding and hence started focusing on prototypes, to be sold as designs to larger players.

Around this time, George Sullivan — the founder — met Stoner, who went on to develop what we know now as the AR-10. The 7.62x51mm design was supposed to be a replacement for the M1 Garand, then used by the US military, but lost out to the Springfield M14 because it failed field torture tests.

Undaunted, the duo continued research and development on a smaller caliber rifle.

The AR-15 Is Born


Word was soon out that the M14 was no match to the AK-47, which had a much lighter ammunition (7.62x39mm), and Stoner was asked to design a rifle on a smaller calibre to combat this problem. The result was the AQR-15, which was chambered to fire .223/5.56mm rounds that were much lighter than the 7.76mm variants. But for some reasons, the AR-15 lost out again to the M14. Eventually, Sullivan sold rights to both the AR-10 and the AR-15 to Colt in 1959.

Eventually, the military was ordered to adopt the AR-15 after full-scale tests in 1963, and the rifle was rechristened the M16. Despite some initial hiccups, the M16 went on not only to rival the AK47, but continues to be the design of choice for a lot of armies the world over.

The Modern-Day AR-10

Modern Day AR10

Like the name suggests, the AR-10 is lightweight (7.25 lbs unloaded), gas operated, air-cooled rifle that fires a 7.62x51mm cartridge, but there are varieties of chambering available. The rifle is light because of its substantial use of aluminum alloy. The only exceptions would be the bolt, steel barrel, handguard, pistol grip, buttstock and bolt carrier.

In overall length, the AR-10 measures 1.029 meters, with a barrel length of about 20 inches.

Workings Of An AR-10

The Firing Mechanism

The propellant gas is bled to a port in the gun barrel and goes to a piston that runs parallel to the barrel. Because of the gas, the piston is pushed and enables the bolt to re-cock, extract the spent cartridge and insert a new one, making the gun ready to shoot again. Stoner’s design though has the gas bleeding through a cylinder that runs parallel with the barrel to affect the bolt carrier mechanism. As a result, the gun has a higher rate of fire ( 700 rounds/minute), and a muzzle velocity of 2,222 feet/ second.

The excess gas is vent through holes on the side, making the rifle air cooled.

The Receiver

To reduce weight, the AR-10’s receiver is made from aluminum, and the bolt locks into the extension of the steel barrel. The pistol grip and the handguard are fibreglass, while the stock of the rifle is a composite reinforced fibreglass.

The Sights

The rear sight of the weapon is contained in a carrying handle, that protects the charging/cocking lever; the other sight is mounted high.

The Modern-Day AR-15

Modern Day AR15

Just like the AR-10, the AR-15 is lightweight (around 5.5-8.5 lbs), and offers reduced recoil. Its ease of customization and conversion has made it one of the world’s most popular semi-automatic rifles. Similarly, the manufacturing makes heavy use of aluminum and synthetic polymers.

The  AR-15 (in a 20-30 round capacity) uses a 5.56x45mm cartridge. Also, like the AR-10, the AR-15 is also available in a wide variety of chamberings. In overall length, the AR-15 measures 1.006 meters, with a barrel length of 0.508 meters (similar to the AR-10).

Workings Of An AR-15

The Firing Mechanism

The AR-15 uses the “direct gas impingement” system used in the AR-15, with the only difference being the wide variety of calibers on offer. The operation gives the AR-15 a cyclic rate of fire of around 800 rounds per minute, with a muzzle velocity of about 3,200 feet per second.

The Sights

Like the AR-10, the rear sights of the weapon is on top of the receiver and a holder (used to carry the rifle like a suitcase) that protects the charging/cocking lever; and an elevated front sight.

The Receiver

Since there is a marked size difference between the calibers of the AR-10 and AR-15, the lower receivers are not interchangeable. The building materials used in the manufacture are the same, even though aluminum remains to be the most preferred. But because of the rifle’s customizability, gun enthusiasts experiment with a lot of other materials as well.

Differences Between The AR-10 And AR-15

Both the weapons are virtually identical when it comes to their appearance. The main difference between the two is the caliber, and as a result, more differences arise. These are barrel rifling, magazine capacity and ballistics.


Though the AR-10’s 7.62mm rounds have longer maximum effective range, the smaller 5.56mm round of an AR-15 travels at a much higher speed. On the other hand, the bigger round has much more stopping power. While the much higher rate of fire of the AR-15 translates into much more hits and hence, is preferred by security personnel since one shot is what it mostly takes to accomplish the job in such situations, the AR-10 has many takers in the big game hunting and the sniper community.

Still, the AR-15 is preferred by gun enthusiasts simply because of its easy access to ammunition and parts, lighter recoil, versatility and low maintenance compared with the AR-10.


The AR-15 is the more available of the two and is among the most popular rifles in most towns where guns are used. Even a simple online search will throw more results for the AR-15, and gun stores will have more variants, compared with the AR-10.

Gun Size

While collapsed, the AR-10 is 35.5 inches and 39.5 inches when extended. The AR-15, on the other hand, is 36.6 inches when extended and 33.3 inches when collapsed.


With great power, well, comes great recoil. Even though the recoil on the AR-1o is significantly less than its counterparts, it is higher than the AR-15, simply because it uses a much powerful round, and therefore, produces much more force.

Weight And Magazine

Since the AR-10 fires a much powerful round, its internal workings need to be much stronger, and hence its overall weight stands at around 8.9 lbs fully loaded. The AR-15 is about 7 lbs, depending on the ammunition used. Also, because of the larger cartridge size, the magazine capacity is reduced in the AR-10 at around 25, as compared with the 30 round capacity of the AR-15.

The weight difference may seem unimportant, given it is only a few grams, but eventually, it is the add-on accessories (standard and third party) that will ultimately make the difference.

The AR-15’s magazine is more versatile too, when it comes to interchangeability from one type to another. On the other hand, the AR-10 is a bit rigid in the sense that it only accepts the AR-10 proprietary magazine.

Comparison Table

Product Name




Modern Day AR10

AR-10 is lightweight (7.25 lbs unloaded)

Air-cooled rifle that fires a 7.62x51mm cartridge

AR-10 measures 1.029 meters, with a barrel length of about 20 inches


Modern Day AR15

AR-15 is lightweight (around 5.5-8.5 lbs)

AR-15 (in a 20-30 round capacity) uses a 5.56x45mm cartridge

AR-15 measures 1.006 meters, with a barrel length of 0.508 meters (similar to the AR-10)

Concluding Notes

We have seen that there isn’t much difference between the AR-10 and AR-15, and that both are historically significant rifles. Now that the differences and similarities between the two have been listed above, it is clear that the main difference between them is the caliber. Both have the same accuracy at distances such as 400-600 yards.

All said and done, there is virtually no difference between the two weapons when it comes to civilian applications. The looks of both guns can be changed in no time by simply replacing or adding the untold number of accessories such as combat grips, tactical rails, bipods and folding stocks that manufacturers have to offer.

If you are into big game hunting and stopping power is what you are looking for, the AR-10 is a great gun. But if you are looking for a lightweight, reliable semi-automatic rifle with great accuracy, you should pick the AR-15, simply because of the number of accessories and ammunition available for it.

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