Patent ID: 6374720
Filing Date: 2002-04-23
Classification: F41A

Abstract:
A firearm comprising:a barrel having rifling; and a device for adjusting the volume available to the expansion of combustion gases as to regulate the pressure developed, in the volume available to the expansion of combustion gases, during firing of said firearm such that said firearm is suitable to the employment of ammunition having differing charges, said device comprising: (i) an expansion chamber connected to the barrel of said firearm through at least one connection hole of the barrel disposed near the beginning of the rifling; (ii) a front calibration screw, capable of being rotated into or out of said expansion chamber to calibrate said firearm for a particular ammunition; and (iii) a back calibration screw, capable of being rotated into or out of said expansion chamber to calibrate said firearm for a particular ammunition, wherein said expansion chamber is parallel to said barrel and is located in a lower-back portion of said barrel or in an upper portion of said barrel, said expansion chamber comprising an inside threading capable of engagement with said back calibration screw and said front calibration screw, said front calibration screw capable of being operated manually by a threaded knob.