Originally manufactured in 1907, this Rock Island Arsenal Model 1903 rifle is one of 4,700 subsequently modified in 1942 into carbine configuration by Ordnance shops in the Panama Canal Zone for use by the 158th Infantry of the Oklahoma National Guard who was stationed there; nicknamed the "Bushmasters" in praise for their advanced jungle fighting skills, a symbol shared with the dangerous pit vipers they encountered while in Panama, the longest venomous snakes in the New World. In 1944, the 158th Infantry Regiment was reassigned to the Pacific on combat duty, where they successfully fought many hard battles. General MacArthur stated, "No greater fighting combat team has ever deployed for battle." It is believed that these modified rifles were disposed of prior to the 158th Infantry's deployment to the Pacific due to them receiving upgraded weaponry, and nearly all of these rifles were sent to Raritan Arsenal in New Jersey and subsequently destroyed after their use in Panama, with this example a rare exception. The unmarked barrel is correctly shortened to 18 inches and refinished blue due to the Ordnance shops in Panama not having Parkerizing capability, and the stock is shortened at the front. It has hooded blade front and arsenal replacement adjustable ladder rear sights, standard receiver markings, "BF" marked arsenal replacement bolt, an open box "SP" arsenal rebuild cartouche marked on the left wrist of the stock, partial "FT CLAYTON" ahead of "JSP" (Jungle Security Platoon) above a large circled "Hellgate" insignia of the Panama Mobile Force marked on the left of the buttstock, and a checkered steel trapdoor buttplate. An included old handwritten note, located inside the butt compartment, states, "...Purchased from K-Mart, San Antonio in 1968 for $69.95, from a crate sent from Panama. Used by the Jungle Security Platoon, out of Fort Clayton, C.Z. [Canal Zone]..." Also includes an M1907 leather sling. Information on these Model 1903 "Bushmaster" rifles can be found on pages 82-83 of "The Springfield 1903 Rifles" book by Lt. Col. William S. Brophy.