After decades as a direct gas-operated rifle, the AR-15 has now blossomed into short stroke piston systems with variations offered by most major manufacturers.
In reality, the AR-15/M16 has always had both a gas piston and cylinder, but its inventor, Eugene Stoner, employed these components in a revolutionary way. Gas is tapped from the barrel as usual, but it is then fed directly to the bolt group through a stainless steel tube, thus the term “direct gas” to describe its operation, but there’s much more to it.
After decades as a direct gas-operated rifle, the AR-15 has now blossomed into short stroke…
by Ed Lovette / Dec 1, 2007