The A-91 retains the simple gas-operated, rotating bolt action and a trigger unit design from the 9A-91, it features a bullpup polymer housing, with an integral 40 mm single-shot grenade launcher mounted under the barrel. The earliest prototypes of the A-91 bullpup were added with the grenade launcher above the barrel, and with a frontal vertical foregrip; current models are fitted with the underbarrel launcher, which serves as a forearm. The A-91 has a forward ejection system, initially developed in Tula by designers like Afanasiev during the early 1960s.
The A-91 retains its gas-operated, rotating bolt action and trigger unit design from the 9A-91. It features a bullpup polymer housing with an integral 40mm single-shot grenade launcher mounted under the barrel. Early prototypes had the launcher above the barrel and a vertical foregrip, while current models have it under the barrel as a forearm. The A-91 has a forward ejection system, originally developed in Tula by designers like Afanasiev in the early 1960s.