| Assault rifle|
| Soviet Union|
| AO-31 (7.62×39mm)
5.45×39mm, 7.62×39mm, Caseless
The AO-31 was a Soviet fully automatic assault rifle chambered for the 5.45×39mm and 7.62×39mm rounds, developed from 1962 to 1964. The weapon is Simonov's adaption of the AK-47 as a result of its reliability.
AO-31-7 was a caseless variant of the AO-31 assault rifle.