Unknown Dev, STEP, IGES, and F3D File Format
The M79 and XM148 grenade launchers were single-shot, and the repeating T148E1 grenade launcher was unreliable, so a request was made to China Lake engineers. Navy SEAL teams were pleased with the resultant pump-action grenade launcher. The tubular magazine held three 40x46mm grenades, and so with one grenade in the chamber, four grenades could be fired rapidly before reloading. In fact, a skilled operator could fire four aimed shots before the first one landed. The grenade launcher was extremely light for its size, since a significant portion of it was made of aluminium.

Submitted for field trials in Vietnam, this weapon apparently performed quite well with HE-Frag ammunition.