December 05, 2006
Direct Gas Impingement.
Gas is tapped from the barrel as the bullet moves past a gas port located under the rifle's front sight base. The gas rushes into the port and down a gas tube located above the barrel. The gas tube runs from the front site base into the upper receiver. Here, the gas tube telescopes over a “gas key� which accepts the gas and funnels it into the bolt carrier. The movement of gas into the bolt carrier forces the bolt and carrier in opposite directions. As the bolt carrier moves towards the butt of the gun, the bolt begins to turn and unlock from the barrel extension. The cam pin is responsible for the bolt's rotation as it follows a groove cut into the carrier that twists and permits the bolt to unlock. Once the bolt is unlocked, the carrier continues to move towards the butt of the gun and the chambered casing is extracted.
A return spring located behind a buffer then pushes the bolt carrier back towards the chamber. A groove machined into the upper receiver traps the cam pin and prevents it and the bolt from rotating into a closed position. The bolt's locking lugs then push a fresh round up the feed ramps and into the chamber. As the bolt's locking lugs move past the receiver extension, the cam pin is allowed to twist into a pocket milled into the upper receiver. This twisting action follows the groove cut into the carrier and permits the bolt to twist and “lock� into the barrel’s extension.
I knew you wanted needed to know this.
Cool Runnings!!!
Posted by Yabu at December 5, 2006 11:04 PM | General
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.. nothing like learning about a black gun, man.... keep reading....
Posted by: Eric at December 6, 2006 06:31 PM
That sounds like my first introduction to the M1 Garand way back when.
Posted by: Pixelkiller at December 6, 2006 09:45 PM
