A look at hand cannon for airsoft use available at Evike.com, the APS THOR PowerUp 40mm Airsoft Grenade Launcher... "The APS THOR stand-alone grenade launcher further extends the APS lineup of innovative Airsoft 40mm grenade accessories. The THOR trigger mechanism has been designed for quick activation to take full advantage of your Airsoft 40mm grenade shells, potentially improving shell output by 150%.

APS has designed the THOR with portability in mind, integrating a Quick Detach Belt Loop and attachment allowing the user to easily stow the launcher on their tactical belt or MOLLE vest when not in use. Additionally the THOR has provisions for mounting 20mm accessory rails (sold separately)."