US Patent 9500420 Caseless projectile and launching system

A launcher system includes a launcher having a barrel adapted to receive a projectile and a charge of propellant and a velocity variator configured to shift relative to barrel to selectively vary a launch velocity of projectile from launcher. The velocity variator may be constituted by a collar selectively controlling the propellant gases vented out of projectile and into barrel and/or a sliding breech face behind which is an energy-absorbing plug.