Testing in the early 1920s led the Ordnance Bureau to identify three rifle designs - the
Bang rifle, the
Thompson Autorifle, and the primer-protrusion actuated
Garand Model 1919 rifle - as promising candidates. However, all three designs were burdened with the high pressure and heat generating characteristics of the .30-06 ammunition, which looked likely to result in a weapon too heavy and too subject to overheating to be worthwhile.
Trials with a small number of "militarized" .25 Remingtonautoloading rifles, despite their unsuitability for combat, provided a body of practical experience with semiautomatic rifles and an appreciation for the idea less powerful ammunition might be a critical part of the successful development of such weapons.