The OICW was a unique and complex weapon that combined the capabilities of an assault rifle and a grenade launcher. It featured a bullpup and a regular rifle design. With the grenade launchers magazine behind the trigger, and the standard rifle trigger in front of the trigger. The OICW was chambered in the 5.56x45mm NATO cartridge. The OICW also featured a built-in 20mm grenade launcher that was capable of firing a variety of explosive and non-lethal rounds.
The weapon's development progressed to mock-up stage before being terminated, as the ATK/H&K design was selected over AAI OICW, and received the contract for prototype manufacture.
