Rocket Surgery: Inside the Russian Nikonov AN94
16m
The AN-94 Nikonov is one of the recent series of innovative new small arms coming out of the Russian Federation. In this case, it is an attempt to increase hit probability by firing two rounds before the recoil impulse changes the shooter's point of aim - similar to some of the US SPIW project experimental rifles.
The Nikonov accomplishes this with a combined gas- and recoil-operated system, and a feed system with a third position between the magazine and chamber. When in 2-round-burst mode, it fires both rounds at about 1800 rpm. Normal fully automatic mode runs at a much more conventional 600 rpm, because the burst function can only work for two rounds successively before needing to reset. It functions by using a pulley and steel wire to use the rearward motion of the bolt on the first shot to pull a cartridge forward into position to feed while the internal receiver unit of the weapon is recoiling backwards. The second round fires as the receiver unit reaches full travel, and because the recoil is only felt by the shooter when the receiver unit hits its full rear position, this allows both rounds to already be downrange before the sights move. Contrary to popular myth, the pulley has nothing to do with balancing recoil forces in this rifle.
The AN94 is, of course, very complex and quite expensive. While it was officially adopted by the Russian military, it has not seen extensive service, and is certainly not being widely issued.