AR-15 operating systems have traditionally relied upon a technology known as direct impingement. With direct impingement, the firing pin strikes the primer and delivers the bullet down the barrel of the weapon, which causes the propellant gas to accumulate behind the bullet. The gas then bleeds out through a small hole in the barrel and is channeled into the gas tube. Next, the gas “impinges” the bolt carrier mechanism, causing the bolt to move in a backward motion and compress the buffer spring. The spring then continues the cycle by picking up the next round.
The Advent of AR-15 Piston Systems
A more recent innovation is the AR-15 piston system, which is also a gas-based operating system. How AR piston systems work is not significantly different from the manner in which direct impingement technology operates. The major distinction is that the gas is forced into a separate cylinder instead of the gas tube. The cylinder contains a piston that causes the bolt carrier to move backward to manage the extraction and ejection process.
Key Points About How AR-15 Piston Systems Work
Because they are relatively new, many gun owners are still somewhat unfamiliar with how AR-15 pistons work, as well as their potential advantages and disadvantages. Perhaps the biggest benefit is that the piston systems operate much cooler and cleaner than direct impingement systems. You can actually hold the bolt carrier in your hand without fear of burning even after firing 100 rounds in rapid succession. The magazine will also continue to look clean even after firing. This can be especially advantageous to military and other users who may engage in intensive firing activities.
On the downside, AR-15 piston systems add about a pound of extra weight to the weapon, which could be a big disadvantage to those who prefer a lighter, more nimble gun. Although the piston is regarded as accurate and reliable, they do produce more recoil, which can slightly affect accuracy on follow-up shots. The higher cost may also be a drawback for some gun owners — expect to pay up to $500 more for a gun with an AR-15 piston system as opposed to its direct impingement counterpart. Finally, piston systems typically are not as suppressor-friendly as direct impingement systems.
Contact Wing Tactical to learn more about how AR piston systems work and whether piston or direct impingement systems are the better choice for you.