AR-15 Diagrams & Nomenclature

Below are the sub-systems of the AR-15 carbine/pistol/rifle. These diagrams are for the standard handguard versions, free float handguards will be slightly different.

Lower Receiver Diagram
Lower Receiver
Buffer Diagram
Buffer Assembly
Upper Receiver Diagram
Upper Receiver Assembly
Bolt Carrier Diagram
Bolt & Bolt Carrier
Barrel Assembly
Barrel Assembly