Difference from AR rifles and Gas Piston rifles

[Buddhabelly]

You can use the 89 Octane. No need to go 91.

On the other hand, having bad Mexican food may be sufficient for many cases.

[swerv512]

Pay attention boys and girls, this is the AR buying public right here:
Quote:
Originally Posted by Secret
Hey, noobie here looking to put together my first AR soon.
Do i have to buy gas for the gun, or does the gun somehow make the gas