This is an incredibly rare example of a prototype Pedersen Model GX self-loading (semi-automatic) rifle bearing serial number "1". This rifle was developed by firearms inventor John D. Pedersen in the late 1930s. Following the Army's decision to stop development of rifles chambered in .276 Pedersen caliber, and to instead continue further development of John C. Garand's rifle design in .30-06 Springfield caliber following early 1930s service rifle trials as opposed to John D. Pedersens T1 toggle lock rifle, John D. Pedersen subsequently developed a new rifle design with intent of again competing against the, then officially adopted, M1 Garand rifle; in spite of losing to the Garand rifle and frustrations over claims that some of his patented designs were stolen and used by the government in the M1 Garand rifle. The example we have for sale here is a GX model rifle that combines features of the M1 Garand and T1 Pedersen rifles with improvements. There are also a very limited amount of surviving examples of GY model rifles that were developed directly after this rifle. This Model GX rifle utilizes a "gas trap" system and is only able to use John Pedersen's proprietary en bloc clips for loading (not included), and the Model GY utilizes a "gas port" system and the later adopted M1 Garand en bloc clips. This rifle design is covered under U.S. patent number 2,330,737, originally filed July 29th, 1939 and granted September 28th, 1943, as well as U.S. patent 2,364,549 relating to the means of assembly, and U.S. patent 2,264,809 for the rear sight. This rifle has a separate barrel mounted gas cylinder, handguard, operating rod, barrel with spiral cooling ribs, Pedersen's patented fully adjustable rear sight with 1/2 minute windage adjustments and elevation calibrated from 200-1,200 meters, full length stock with grasping grooves and cooling vents and a unique rotating/telescoping bolt design (very advanced when compared with the M1 Garand). The bolt itself has three opposing lugs, with the top right lug stamped with a "P" proof and the top left lug serial numbered "3". The left of the receiver is marked with the serial number "1" followed by the two-line legend "PEDERSEN SELF-LOADING RIFLE/MODEL GX CAL. .30 U.S." The metal components all have a dull military blue finish and an oil-finished black walnut stock and handguard. Author Bruce Canfield discusses these rifles briefly on pages 189-191 of "The M1 arand Rifle". He states that John Pedersen developed the GX rifle circa 1939 and submitted the rifle to Springfield Armory for testing in 1943, and indicates few examples of the GY rifles are known; serial number "3" is located in the Springfield Armory Museum and the second example is in an un-identified private collection. Rock Island Auction Company previously sold GY rifle serial number "4" (Lot 564, Auction 84) and GY rifle serial number "5" (Lot 3485, Auction 64). This is one of only a handful of GX rifles ever manufactured, with one other surviving example of a GX rifle now known by the writer to exist (serial number 3). Provenance: The Robert Bretherton Collection; Property of a Gentleman