Abstract: The present disclosure provides a projectile with a self-contained internal chamber. Reaction of propellant inside the internal chamber can generate high pressure and the resultant exhaust gases can be used for projectile linear acceleration, rotational acceleration or other purposes. Torque can be produced by exhausting the pressure via radially placed, tangential nozzles or other outlets and can be configured to induce sufficient projectile spin to stabilize the projectile without the need for barrel rifling. The internal chamber may be separate or integral to the projectile itself. The projectile may include two or more chambers or compartments internal to the chambers. The disclosed projectile allows for higher pressures in the internal chamber than in the barrel and greater flexibility on pressure manipulation in the barrel and the projectile, allowing for a more efficient propellant combustion and manipulation of projectile characteristics such as muzzle and rotational speeds.