Model Variants (Including Prototypes)
M1903 (Standard) - Fitted with a rod bayonet; chambered for M1903 220-grain cartridge round-nose bullet; refitted with rear-sight leaves in 1906; no pistol grip in stock design; forend finger grooves.
M1903 Mark 1 - Ejection port introduced for spent shell casings of Pedersen Device; produced in 101,775 total from 1918 to 1920; reworked to M1903 Standard after World War 1.
M1903 "Special Target" - Specialized competition variant with high-end finish and components; redesignated as M1903A1 in 1928.
M1903A1 - Standardized United States Army infantryman rifle beginning 1929 based on target models; pistol grip implemented into wooden stock/body; milled trigger; sans finger grooves along forend; limited production.
M1903A2 - Artillery-modified training piece; not standard-issue personnel weaponry.
M1903A3 - Simplified mass-production variant based on M1903A1; steel-sheet stampings in construction; fitted with a rear adjustable aperture sight (replacing original leaf); rear sight relocated near of bolt.
M1903A4 - Standard Sniper Rifle variant; sans iron sights; permanent mounting blocks for telescopic sights; standard optics was W.R. Weaver Company Model 330 (Telescope Sight M73B1).