This is an extremely rare example of the original Pedersen "T" series toggle lock mechanism test carbines that was developed after the rifle version in the late 1920s. This model features a retarded blow-back, toggle-jointed mechanism as developed by the already famous John D. Pedersen, who was an innovator and firearms designer in his own right. After WWI he advocated that semi-automatic rifles should be easier and lighter, shooting a lighter weight cartridge that developed less heat and recoil. It was this same concept that led him to design the famous Pedersen device to convert Model 1903 bolt action rifles into Semi-Automatic rifles, a concept way ahead of its time. In this new design he developed the radical .276 Pedersen cartridge firing a much lighter bullet than the 30-06 which was eventually tested (and competed) along with his toggle-jointed mechanism against the M1 Garand rifle in the 1930s. He is also credited with developing the "en-bloc" cartridge clip design, with the only flaw being his clip was unidirectional (ie it had to be inserted in one directly only) while the John Garand designed clip was reversible allowed it to be inserted form either direction. His original rifle designs were designated the T1 series rifles and the then prototype M1 Garands were the T3 series rifles. This model as noted is the calvary carbine version of Pedersen original design designated the "T2-E1" series. It featured the same original toggle-jointed mechanism (like the German Luger) only in a carbine version. The left side of the receiver is marked "U.S. SEMI-AUTO RIFLE-T2-E1/CAL-.276-PEDERSEN PATENTS". followed by a British "NP" proof. The right side is stamped with only serial number "1". It is fitted with a 22 inch barrel with the shortened walnut half-stock but still retains the perforated sheet metal handguard and fixed extended box magazine chambered for the noted .276 Pedersen cartridge. It has the fully adjustable rear sight with the fixed high front sight. This is an unbelievably rare test model of the original Pedersen rifles and carbines. This super rare carbine is complete with a WWI era leather sling, one unidirectional en-block clip loaded with 10 rounds of original .276 ammunition and a full box (20rds) of the original .276 Pedersen cartridges. Provenance: The George Moller Collection