AR 15 rifles are some of the most versatile firearms available today, so it makes sense that AR 15 upper receivers are available in a large variety of makes and models to suit any gun enthusiast. The upper of your AR-15 is almost as important as your lower. As the lower is the heart and soul of the AR15, the upper is the arms and legs.
This is the part of the gun that controls the bullet. Giving the bullet direction is the primary responsibility of the AR15 upper. The AR 15 upper could be divided into 9 different components. The components are
(1) A2 Rear Sight Assembly,
(2) Production Codes,
(3) Carry Handle,
(4) Barrel Attachment Point,
(5) Front Pivot Pin Lug,
(6) Ejection Port Cover,
(7) Case Deflector,
(8) Rear Takedown Lug, and
(9) Forward Assist.
The A1 AR 15 upper receivers, come with a carry handle and are especially popular because they make transport easier. This receiver is most often used by hunters who have to carry their guns long distances in the field. The A3 flat top AR 15 upper receivers are popular because they often come with Picatinny rail systems. This type of upper allows for easy accessorization and addition of sighting systems such as scopes. Especially suited for long-range shooting, the A3 flattop AR 15 upper receiver is often found on sniper-style AR 15 rifles.