AR Sponsor
Posted: 1/25/2009 6:31:09 PM EDT
|
Just got my first AR. Very basic question. What does the gas block do?
Thank you. |
|
AR's use the expanding gas that travels down the barrel to push the bolt back to cycle another round. What happens is, the firing pin strikes the primer, ignites the powder, bullet fires, gasses expand. The gas block is basically a block that fits over the barrel and gas port. This is the point where the extra gas leaves the barrel through the gas port, travels trough the gas tube which is anchored inside the gas block, which then proceeds to push the bcg back extracting the spent round and cambering a new one.
The system that the ar mainly uses is known as direct gas impingement. 
The blue square is where the gas leaves the barrel through the gas port and then travels down the gas tube which is anchored in the gas block. This is also where you would install an aftermarket gas block if you wanted to. This is different than a piston system, where the expanding gasses are used to push a piston rod, which in turn pushes the bcg back. |
AR Sponsor