Winchester model 30

The Winchester Model 30 was an experimental self-loading rifle developed by Winchester Repeating Arms as a potential alternative to the M1 Garand for the U.S. military. Following early interest from the Ordnance Department, Winchester acquired production rights to a self-loading .30-06 Springfield design by Jonathan E. Browning and modified it with a short-stroke piston system developed by David Marshall Williams, which was later used in the M1 carbine.

The rifle underwent testing as various prototypes: the G30, tested at Aberdeen Proving Ground in 1940; the G30M, tested by the Marine Corps alongside other rifles and found less satisfactory than the Garand; and the G30R (later designated T10E1), which featured detachable magazines but was still deemed inferior to the Garand. In response to requests for a selective fire capability, Winchester developed the Winchester Automatic Rifle (WAR) in 1944, which weighed less than the M1918 Browning Automatic Rifle (BAR). Further testing by military boards in 1945 ultimately concluded without adoption due to the end of World War II.