Probing on Barrel Life for the Small Caliber Gun

For the small caliber automatic gun,normal firing rate is 550rpm for type A and 1 000rpm for type B.The material,bore shape and process scheme of barrels and using cartridge are entirely same for the two type automatic gun.But the life of barrel for type B automatic gun is 64%~70%of type A automatic gun in gun life test when adopting same firing specification.Heat analysis for the bore is made at the base of practically measured temperature at the barrel's out surface in firing process,the reason of barrel life decrease is discussed by analyzing the increase of barrel temperature.Reasonable firing specification is made when the bore temperature can not exceed its material phase change critical temperature,thus it can increase the barrel practical life.