With the death of Jonathan "Ed" Browning in 1939, development of the Winchester G30 rifle was passed into the hands of a new employee at Winchester by the name of David Marshall Williams. Williams would become widely known as "Carbine" Williams in later years thanks to Jimmy Stewart and Hollywood, but we will be to that part of this story later.
What Williams did to the G30 was to replace Browning's annular gas piston with his own short stroke tappet system (this being the first rifle to use that system of Williams'). This substantially improved the gun's reliability, and Winchester was able to submit it to Marine Corps trials in 1940 alongside the Garand and Pedersen rifles under the designation G30M. The Marine Corps was legitimately interested in the G30M, as it was expected to be both faster and cheaper to manufacture than the Garand.
Ultimately the trials were won by the Garand, with the G30M placing third in total malfunctions and broken parts. This had involved 37 different tests and more than 12,000 rounds through each rifle. The Garand had 1,480 total malfunctions and 49 parts broken, replaced, or repaired. The Johnson had 1,547 and 72 respectively, and the G30M 2,864 and 97 (roughly double the number of problems as the Garand).
Despite this failure, Winchester was encouraged to continue working on the rifle, if for no other reason than the possibility of foreign purchasers. Williams' next step would be to replace the Browning tilting bolt with a Garand-type rotating bolt, which would result in a rifle Winchester would call the M2, or "the seven and a half pound rifle". We will examine that rifle in the next video...