FYI the AR has a piston, its in the bolt and carrier interface...
Stoner made the AR-16 (he liked 7.62NATO better than 5.56mm) in a DI version first, but since he had sold the rights to the DI rotary lock design to Colt, he was forced to make it a piston, the AR-18 was the 5.56mm scaled version of the AR-16.
We have a AR-16 prototype here - you can see where he pinned part of the piston in where the gas tube was, and the carrier and bolt where originally designed for DI.
Its actually a facinating gun, and one I want to build in DI (folding stock DI gun whats not to like).
Stoner made the AR-16 (he liked 7.62NATO better than 5.56mm) in a DI version first, but since he had sold the rights to the DI rotary lock design to Colt, he was forced to make it a piston, the AR-18 was the 5.56mm scaled version of the AR-16.
We have a AR-16 prototype here - you can see where he pinned part of the piston in where the gas tube was, and the carrier and bolt where originally designed for DI.
Its actually a facinating gun, and one I want to build in DI (folding stock DI gun whats not to like).



















































