Patent ID: 8297174

Claim:
A weapon, comprising: a translatable recoil mass including a barrel and a barrel block; two translatable counterweights disposed on opposite sides of the recoil mass, each counterweight having a mass that is substantially one-half a mass of the recoil mass; a pair of racks fixed to respective ones of the counterweights, a second pair of racks fixed to opposites sides of the recoil mass, and a pair of pinions, each pinion engaging a counterweight rack and a recoil mass rack; a receiver that is fixed with respect to the recoil mass and the pair of counterweights; an inertial spring that transfers recoil force to the receiver; wherein directions of translation of the recoil mass are substantially opposite direction of translation of the two counterweights; wherein the inertial spring transfers force by compressing against the receiver; a plurality of mounting rods having ends fixed to front and rear plates, wherein the recoil mass and the counterweights are slidable on respective ones of the mounting rods; and a positioning spring disposed on one of the mounting rods.