The Mk. 31 "Bullshark" Grenade Launcher is a concept magazine-fed grenade launcher that is made by Mayfield Heavy Industries, a subsidiary of Rickard Firearms & Defense. Although currently a concept design, it would be Rickard-Colmans Group's first grenade launcher put into production.
- Barrel is 14 inches long.
- Chambered for 40mm grenades, and is fed via a 5-round magazine.
- Designed in 2011.
- Effective range is about 400 meters.
- Four-position collapsible stock.
- Rate of fire: Semi-automatic.
- Weighs 10.5 pounds.