==Caliber: 6,5x50SR Arisaka Action: short recoil operated Overall length: 1045 mm Barrel length: 520 mm Weight: 4,4 kg empty Rate of fire: 600 rounds per minute Magazine capacity: 25 rounds == Captain V. Fedorov of the Russian Imperial Army (later - a general of Soviet Army) started development of the self-loading rifle in 1906. His first rifle was chambered for standard Russian 7,62x54R ammunition, held 5 rounds in fixed magazine and fired only semi-automatically. In this job Fedorov was supported by his apprentice V.Degtyarov (who latter became one of most important Soviet small arms designers of pre-WW2 generation). Firs Fedorov rifle entered trials in 1911. In 1912 the Rifle Commission of Russian Army decided to order 150 more Fedorov rifles for further trials, and in 1913 Fedorov submitted a prototype automatic rifle, chambered for his own experimental rimless cartridge of 6,5mm caliber. This new ammunition was more compact that Russian 7,62x54R, better suited for automatic weapons (because of rimless cartridge) and has less recoil. This experimental cartridge fired pointed jacketed bullet weighting 8,5 gram at initial velocity of 860 m/s (muzzle energy 3140 Joules as opposed to 3600 - 4000 Joules muzzle energy of 7,62x54R ammunition). 6,5mm Fedorov rifles were tested late in 1913 with good results; these rifles still had fixed magazines loaded from stripper clips. Further trials and development were stopped by the start of World War One. In 1915, however, the need for lightweight automatic arms forced Russian Army to order manufacture of Fedorov automatic rifles with detachable magazines of bigger capacity.