The AAI SMG was a prototype SMG/PDW that fired 18.5mm caliber munitions.
The AAI SMG was designed to fire 18.5mm caliber scimitar flechette rounds and HE grenades developed by AAI, but this limited the magazine capacity to 20 rounds. The weapon was capable of firing at semi-auto or full auto and maintain accuracy to any other firearm in similar caliber.
To increase its capabilities, it also fired HE frag grenades for area effect. This would allow the AAI SMG to engage point targets with the scimitar munitions for improved hit probability of the multiple projectiles fired at the target. The HE frag grenade would be used for group targets, confined interiors of bunkers, etc. through an opening or targets behind cover.
The AAI SMG fires from a closed bolt and uses a delayed blowback operation using a wedge that holds the bolt closed until the gas pressure drops to a safe level to reload the next round. This was meant also to control the amount of energy sent to the bolt and slide so the velocity of travel would not internally damage the receiver, which is made of alloy for weight savings. A fixed/folding stock was also avaliable.
- Future Weapons By Kevin Dockery, Berkley Publishing Group ISBN 13: 978-0-425-21215-8