The AK 47 uses the 7.62x39mm assault rifle round. Several of the definitions below have glaring errors. Firstly the AK47 was one of a new breed of weapon invented by the germans at the end of WWII but never fielded in any great number. The assault rifle uses a cut down rifle bullet in a short rifle cartridege case. This is different than a true carbine that fires a pistol bullet in a scaled up cartride case through a short rifle. This was a new concept meant to provide infantry with a lighter weapon and ammo than the full size battle rifles of the day, without the loss of power assosciated with carbines or SMG's. The russians fielded the german assault rifles in a heavily modified design, using the cartride invented by the germans almost immediately following the war. There is ZERO relationship of the 7.62mm assault rifle round to the 7.62 rounds used by snipers. The American 7.62x51mm "308 Winchester" is almost twice the size and weight of an AK round, and the Soviet Block 7.62x54Rmm "Mosin Nagant" the standard eastern block round, is een bigger. The American adoption of the 5.56x45mm round during the Vietnam war was the result of scientific analysis of engagements during Korea and Vietnam. The range of the full size battle round was unecessary, so the Americans adopted the assault rifle concept taking it an evolutionary step further with a smaller higher velocity round. This was the underapreciated genius of Eugene Stoner. The Russians followed suit shortly after with the AK74 which is mechanically identical to the AK47 but chambered in the 5.45x39 round. Incidetally through no accident the casual design tolerances of the AK74 allow it to fire the American 5.56 round for short periods should the need arise. The M-16 series has tolerances far to tight to allow this. In the future if your going to write a definition try to know what you are talking about.
Snipers use battle rifles like the Druganov, and M-21,not assault rifles like the AK 47. Only a moron would make that mistake.