In February 1926, the new rifle and ammunition were tested in the presence of representatives of both the Army Chief of Infantry and the Chief of Cavalry.
The results were “highly favorable” Production was authorized on May 20, 1926 of 20 rifles and 5 carbines.
Following tests of reworked versions of the Thompson and primer-actuated Garand rifles, the Infantry Board in June, 1926 recommended further testing of all three rifles, but clearly indicated in its report the Pedersen rifle was the most developed of the three.

In April 1928 came the Infantry Board test report on the T1E3, and it was a solid endorsement of the rifle.
The Board called for adoption of the T1E3 rifle to replace both the Model 1903 Springfield and the Browning Automatic Rifle.
The Cavalry Board was also positive in its own evaluation of the T1E3.
To soldiers used to the heavy recoil and exhausting manual operation of the Springfield rifle, the moderate recoil and self-loading functionality of the T1 rifle clearly must have made an impression.
Due to problems with primer-actuation, John Garand gave up work on a .30-06 semiautomatic rifle and also focused exclusively on caliber .276.

Doubts about the lethal effect of the .276 round were strong enough to result in extensive tests in June and July 1928 by the “Pig Board” (so called because lethality tests were carried out on anaesthetized pigs).
The Board found all three rounds (.256, .276, and .30) were wounding out to 1,200 yards (1100m).
At 300 yards, the smaller .256 caliber round delivered "by far the most severe wounds in all parts of the animal."
At 600 yards the results were similar for all three rounds.
No compelling case could be made against the Pedersen round.
In February 1926, the new rifle and ammunition were tested in the presence of representatives of both the Army Chief of Infantry and the Chief of Cavalry. The results were “highly favorable” Production was authorized on May 20, 1926 of 20 rifles and 5 carbines. Following tests of reworked versions of the Thompson and primer-actuated Garand rifles, the Infantry Board in June, 1926 recommended further testing of all three rifles, but clearly indicated in its report the Pedersen rifle was the most developed of the three.
In April 1928 came the Infantry Board test report on the T1E3, and it was a solid endorsement of the rifle. The Board called for adoption of the T1E3 rifle to replace both the Model 1903 Springfield and the Browning Automatic Rifle. The Cavalry Board was also positive in its own evaluation of the T1E3. To soldiers used to the heavy recoil and exhausting manual operation of the Springfield rifle, the moderate recoil and self-loading functionality of the T1 rifle clearly must have made an impression. Due to problems with primer-actuation, John Garand gave up work on a .30-06 semiautomatic rifle and also focused exclusively on caliber .276.
Doubts about the lethal effect of the .276 round were strong enough to result in extensive tests in June and July 1928 by the “Pig Board” (so called because lethality tests were carried out on anaesthetized pigs). The Board found all three rounds (.256, .276, and .30) were wounding out to 1,200 yards (1100m). At 300 yards, the smaller .256 caliber round delivered "by far the most severe wounds in all parts of the animal." At 600 yards the results were similar for all three rounds. No compelling case could be made against the Pedersen round.
Pedersen rifle