Whats the difference between the 1903 Springfields on CMP? Springfield, MK1 Springfield, Remington?
The Spingfield is the basic M1903, made at Springfield and Rock Island arsenals up through the 20s. The MKI as mentioned earlier has the milled ejection cutout for the Pedersen .30 caliber cartridge, and the modified sear to allow it to use the Pedersen device (officially called "US Pistol, Model 1918.") The Pedersen device was inserted in the receiver in place of the bolt and allow the rifle to fire very low-powered cartidges semi-automatically. The idea was to use it as a trench-clearing weapon --but the war ended before any were ever used in combat. Most were destroyed in the 1920s.
In 1940, we had a shortage of rifles. The government armories were making Garands as fast as they could, so the Springfield tooling was delivered to Remington, who made M1903s as "second class" or "class B" arms. The Remington M1903s are some of the best ever made.
Shortly after starting the contract, Remington suggested some changes to the Army to make the rifle cheaper and faster to make. The result was the M1903A3 -- not to be confused with the "Remington M1903."
The M1903A3 makes considerable use of stamped, not milled, parts in non-fuctional areas (trigger guard, floor plate, bands, butt plate) and a cheaper peep sight mounted on the receiver bridge (which ironically is better than the standard Springfield sight for combat use.) Some M1903A3s have two-groove barrrels -- which shoot just as accurately as 4-groove barrels.
