By May 1941, the U.S. Ordnance Dept. had started trials of a number of submissions for a light rifle design that would eventually be chambered for the .30 caliber Carbine cartridge. Winchester initially decided against developing a submission because of other commitments that included the Browning prototype being worked on by Williams. During the trials of the Model G30M at Quantico and San Diego, it had become apparent to Winchester they were not going to be able to replace the M1 by Garand. When Williams produced the Model G30R, it convinced Winchester they should be able to come up with a prototype for the light rifle trials.