Pressure relief valve for providing recoil to blank-firing weapons

In combination with a weapon barrel used for firing blank cartridges, said barrel having a bearing support slidably mounted thereto adjacent its muzzle end, the improvement therewith comprising a pressure relief valve having a nozzle threadedly mounted to the muzzle end of said barrel and interiorly said bearing support, said valve further comprising,

• a conically shaped portion foward said nozzle,
• a valve tip forward said conically shaped portion, said valve tip having a forward and rearward portion,
• a slotted passage disposed within said conically shaped portion of said valve and between said rearward portion of said valve tip and said nozzle and communicating with said nozzle to permit flow of propellant gases from a central orifice in said nozzle to said valve tip,
• a gas assist chamber surrounding said slotted passage and said conical portion of said valve, said gas assist chamber having an inner wall comprising said conically shaped portion of said valve and an outer wall comprising a conical surface disposed within said bearing support, said bearing support conical surface being similarly configured as the valve conical surface and spaced therefrom,
• an exhaust port forward said valve tip, said gas assist chamber being sealed at a forward portion by said valve tip to prevent gases from escaping through said exhaust port, said gas assist chamber communicating with said muzzle and said valve tip, the cross-sectional area across face of said muzzle at which gas exerts a backward force when a blank round is fired being greater than the cross-sectional area of said rearward portion of said valve tip at which gas exerts a foward force to thus provide recoil to said barrel when propellant gases flow through said barrel bore and nozzle and into said pressure relief valve, said recoil providing unsealing of said valve tip from said gas assist chamber and thus allowing propellant gas venting through said exhaust port.