On 13 August 1928, a semiautomatic rifle board (SRB) carried out joint Army, Navy, and Marine Corps trials between the .30 Thompson, both cavalry and infantry versions of the T1 Pedersen, "M1924" Garand, and .256 Bang, and on 21 September, the board reported no clear winner. The .30 Garand, however, was dropped in favor of the .276. Further tests by the SRB in July 1929, which included rifle designs by Browning, Colt–Browning, Garand, Holek, Pedersen, Rheinmetall, Thompson, and an incomplete one by White, led to a recommendation that work on the (dropped) .30 gas-operated Garand be resumed, and a T1E1 was ordered 14 November 1929. Twenty gas-operated .276 T3E2 Garands were made and competed with T1 Pedersen rifles in early 1931. The .276 Garand was the clear winner of these trials. The .30 caliber Garand was also tested, in the form of a single T1E1, but was withdrawn with a cracked bolt on 9 October 1931. A 4 January 1932 meeting recommended adoption of the .276 caliber and production of approximately 125 T3E2s. Meanwhile, Garand redesigned his bolt and his improved T1E2 rifle was retested. The day after the successful conclusion of this test, Army Chief of Staff General Douglas MacArthur personally disapproved any caliber change, in part because there were extensive existing stocks of .30 M1 ball ammunition. On 25 February 1932, Adjutant General John B. Shuman, speaking for the Secretary of War, ordered work on the rifles and ammunition in .276 caliber cease immediately and completely, and all resources be directed toward identification and correction of deficiencies in the Garand .30 caliber. On 3 August 1933, the T1E2 became the "semi-automatic rifle, caliber 30, M1". In May 1934, 75 M1s went to field trials; 50 went to infantry, 25 to cavalry units. Numerous problems were reported, forcing the rifle to be modified, yet again, before it could be recommended for service and cleared for procurement on 7 November 1935, then standardized 9 January 1936. The first production model was successfully proof-fired, function-fired, and fired for accuracy on July 21, 1937. Production difficulties delayed deliveries to the Army until September 1937. Machine production began at Springfield Armory that month at a rate of ten rifles per day, and reached an output of 100 per day within two years.