The AB-3 was a Soviet assault rifle chambered for an experimental caseless cartridge, 1970.
Work on the caseless rounds began in an interbranch compeition announcd by the Ministry of Defence Industry of the USSR in 1972. The experimental series of machines under the 5.6mm caseless cartridge designed for Izhmash, received the name of AB. A feature of this scheme is the lack of sleeves in the chuck, the bullet is inside the compacted powder bombs, which the shot is almost completely consumed, and therefore there is no need to build the mechanisms necessary for the ejection of shells and reflections, facilitated by the mass of the munition. However, studies have revealed the unsatisfactory reliability of storing caseless ammunition, uneven burning of compressed gunpowder bombs at low and high temperatures (powder crumbles or breaks into pieces), which leads to instability of the pressure in the bore. Also, the rifle's design revealed problems with the obturation at a shot, which in the classical configuration cartridge provides sleeve.