Pedersen rifle

Pedersen rifle
Pedersen's toggle-delayed blowback rifle in caliber .276 Pedersen
Type	Semi-automatic rifle
Place of origin	United States
Service history
Used by	United States Army (testing and field trials)
Production history
Designer	John Pedersen
Designed	1920s
Specifications
Cartridge	.276 Pedersen
Action	Toggle-delayed blowback
Feed system	Fixed 10-round box magazine

The Pedersen Rifle, officially known in final form as the T1E3 rifle, was a United States semi-automatic rifle designed by John Pedersen that was made in small numbers for testing by the United States Army during the 1920s as part of a program to standardize and adopt a replacement for the M1903 Springfield.

Although the Pedersen was rated for a time as the most likely candidate for standardization and adoption, the .30 caliber M1 Garand was chosen instead.

The U.S. Army had shown interest in the idea of self-loading (semiautomatic) rifles before World War I. Combat experience during that war had made clear two general points: that the standard caliber .30-06 rifle cartridge was excessively powerful for the ranges (500 yards and less) where infantry combat was likely to take place, and that bolt-action rifles such as the M1903 Springfield were seriously lacking in firepower and second-shot hit capability. The U.S. Army Ordnance Bureau had no problem in soliciting designs and prototype weapons from inventors, and sought to facilitate their work by supplying barrels and other hardware that the inventors were likely not to be able to fabricate. However, such a traditional way of developing new weapons all too often saw potentially worthwhile designs wash out of the testing process due to a lack of engineering skills and experience both in the design and manufacturing phases.

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 Remington autoloading 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.