The AR-15 rifles are built around the firing pin, unlike the rivals, the SKS and AK47 rifles. The AR-15 uses a gas blow back system to eject and reload each round. Since the beginning of the AR-15 rifles, there have been a wide range of innovations, which include the M4, which consist basically of upper receiver feed cuts. Now the M4 rifle is becoming one of the civilian favorites, due to the versitile design, and ability to quickly change optics, and maintain a lower profile

 The AR15 rifle or Armalite model 15 was created by Eugene Stone with a team of engineers in the 1950’s. Originally the AR15 was designed for the US military’s trials for a new battle rifle, with the AR10 rifle. At that time the US military was looking to replace the M-14, which used the 308 Winchester cartridge.

While working for Armalite Arms, a division of the Fairchild Aircraft & Engine Corporation, Eugene Stoner developed several new rifles that utilized a more non traditional material makeup. Using aluminum alloys and plastics to develop the lighter 5.56 mm version of the AR-10, this cut down on weight, as well as heat of the weapons system.

The AR15 was built around the .222 Remington cartridge, but at the request of the Army, Stoner re-chambered it in the .223 Remington or 5.56 NATO round that propelled a 55-grain bullet at roughly 3000 ft per second, causing the projectile to tumble inside of the target. Since the Geneva Convention ruled hollow point ammunition to be against rules of engagement this projectile cause the same amount of damage while complying with the rules of acceptable military ammunitions.

After various attempts to market the Armalite AR10 and AR15 rifles failed Fairchild decided to dissolve ties to Armalite, which lead to selling the rights of both rifles to Colt Arms. Colt successfully marketed these designs to the US Military, which excluded various design revisions that Stoner had mentioned prior to service use; one of the major changes was chrome lined barrels, which lead to disasters in the Vietnam War.

During the Vietnam War, M16 rifles had a reputation of being prone to jamming, and rusting with bullets in the chamber due to the humid conditions, and lack of chrome lined parts. Another major contributor was the ball powder in the ammunition used at the time, which was particularly dirty considering the gas blow back operating system used, which feed exhaust into the firearms receiver, causing the M16 to need regular maintenance.

Currently, the AR15 has become one the most highly revered battle rifles of the modern era. It has since earned a reputation for reliability and accuracy. Over the last few decades the “M16” is being phased out by the 14.5” M4 carbine. The U.S. Military Special Operations Command also currently issues the M4 to its troops while The Marine Corp uses the M16A4 20” variant. For these Special Forces, the M-4 has also been in certain instances reconfigured to fire "three round burst", as opposed to "full automatic", as well as easily accept most optics with quick release abilities.

Now the AR15 rifles are a civilian must have because of the reduced recoil, fast handling characteristics. Countless companies producing AR15 accessories, it’s hard to imagine the world without this symbol of freedom. The AR15 design is also being rethought with a handful of companies now producing piston conversion kits, which have proven to severely reduce maintenance, and increase reliability. The AR-15 platform has been around for nearly a half century, but is sure to remain one of the most popular rifles for decades to come.