Abstract: A gas rifle which utilizes at least one combustible gas to drive the bullet and which includes a barrel and an associated combustion chamber with two gas storage containers and valve means for feeding gas at a controlled rate from gas supply cylinders into the combustion chamber. The rifle is provided with a pivoting breechblock and a piezoelectric crystal firing mechanism which ignites the gas or gaseous mixture in the combustion chamber by means of an electric spark upon pressing the trigger. Bullets may be fed into the breechblock in manual, semi-automatic or automatic mode of operation by a bullet feed linkage system in cooperation with a clip. A suitable recoil means can be utilized to permit semi-automatic and automatic modes of operation.