[FOX_111]

I'd simply use a mini airbomb as a warhead with a switch in the grenade cone to detonate the mini airbomb on impact with the electric detonator sitting right in the charge for no delay. You'd have to lunch the whole thing with a 9v batterie in it, so the cone would have to be soft enough not to cause injury.

I'm pretty sure it would be light enough to be lunched out of a low velocity compressed air modified M203.

A couple of years ago, we made some testing using hobby rocket motors and black poweder. The warhead was at the time inert or paintball for marking and testing purpose. It was promising.