Inventors have been invited by the United States army’s ordnance department to develop a light machine gun before October, 1941, when tests will begin. In general, the gun must not weigh more than twenty-two pounds nor be more than thirty-eight inches over-all; mounted on its tripod it should not exceed eighteen inches in height. Air cooling is one requirement, and the barrel must be capable of being unscrewed from the front so a new barrel can be put on in a few seconds. It is to be bored and chambered for the standard .30-caliber army cartridge, and heavy enough to fire 300 to 350 shots a minute for five minutes without, stopping. Ammuni tion is to be fed in from the left side, in metal-link belts, the cloth-web belts and box-magazine and clip feeds being considered unsatisfactory. Although there are other specifications, a gun that meets theserequirements, and can stand rough usage under field conditions is said to have a good chance of competing with the best weapons offered for adoption by the army as the standard type.