Patent ID: 8826792

Claim:
A method for launching a projectile from a projectile launcher, the method comprising: a) providing a combustion chamber, wherein a predetermined first pressure in said combustion chamber prior to combustion is selected from ambient pressure to above ambient pressure; b) providing at least one propellant comprising at least one propellant constituent, wherein said at least one propellant constituent at least partially comprises a gas or vapor state prior to combustion in said combustion chamber; c) injecting said at least one propellant constituent into said combustion chamber through at least one injector, wherein a pressure at injection is greater than said first pressure; d) igniting said at least one propellant within said combustion chamber to produce combustion gases; and, e) opening a piston valve in response to said combustion gases, wherein said piston valve comprises a piston and a gas port; wherein moving said piston releases said combustion gases through said gas port, and further wherein said combustion gases pass though said gas port to generate a motive force within said projectile launcher.