AR-15 General Info

AR-15 General information and brief history

The AR-15 rifle was developed by the American Eugen Stoner in the 1950s. To begin with, it is a smaller scaled version of the AR-10 rifle previously developed by Stoner, which fired the 7.62x51 / 308win cartridge. Since then, the AR-15 rifle has been further developed. The main AR-15 calibers are 5.56×45mm NATO or .223. The U.S. Army has defined the AR-15 as a Mil-Spec standard, according to which gun factories that want military or other government contracts make weapons and their parts. They define e.g. parts manufacturing materials, surface treatments, dimensions and tolerances. Consequently, basic parts from different AR-15 manufacturers usually go together without matching.

Different station models use slightly different parts, but the main parts are the same. The upper receiver is available with a fixed carrying handle sight or as a Flat-Top model with a MIL-STD 1913 Picatinny rail on the upper part of the frame. The rail can be attached to a detachable carrying handle sight or a wide selection of other sighting devices, including optical sights.

The picture below shows the M16A2 rifle. It is equipped with a fixed carrying handle sight. However, for the most part, the weapon corresponds to a modern AR-15 rifle.

AR-15 style rifle

AR-15 tyylinen kivääri

 

 

 

 

 

 

 

Barrel

Pictured below is the barrel and the forend grip, as well as all the parts found inside the forend grip. There are many different versions of foregrips with different attachment methods, so not all of the foregrip parts mentioned below may be found in your gun. In some models, the front sight/gas port is attached to the barrel with screws instead of cone shocks.

AR barrel

AR piippu

 

 

 

 

 

 

 

Upper body (Upper)

Below is an A2 type upper frame with a fixed carry handle rear sight. Today, the A3 type Flat-top upper stage is more common, where the fixed carrying handle sight is replaced by a MIL-STD 1913 Picatinny rail. The rail enables the attachment of various optical sights and it can also be used with a detachable carry handle sight, the sight part of which is structurally similar to the fixed A2 carry handle sight.

AR-15 upper frame

AR-15 ylärunko

 

 

 

 

 

 


Rear sight (Sights)

AR-15 rear sight

AR-15 takatähtäin

 

 

 

 

 


 

In the upper part of the upper body there is a tuner (Charging handle), which by pulling back the slide can be brought to the rear position and the gun is cocked. There is a latch on the left side of the tuner, which you press to release the tuner from the back of the gun's upper body. When the slide is released forward by the force of the recoil spring by removing the grip from the tuner, the latch automatically locks into the upper frame. The tuner does not move with the slide.

AR-15 trigger lever

AR-15 viritinvipu

 

 

 

 

 

 

Lower body (Lower)

Below is the underframe and stern with parts. The picture shows an A2 stern. Different station models have different pers, the structure and mechanisms of which vary. The tail tube, recoil spring, and recoil damper of the length-adjustable tele-stern are shorter than in the A2-stern and are therefore not interchangeable.

AR-15 Lower

AR-15 alakerta