There are flying and remote-controlled grenades called the Drone 40, and they really can become airborne explosives.
The flying grenade is a Drone 40 modular quadcopter. It can be either a scout or a loitering grenade. In action, it looks goofy, like someone saw a “Sky Dancer” flying toy from the 1990s and decided it would be a great basis for a bomb.
What sets the Drone 40 apart from a host of other small drone designs is the long, vertical fuselage. Unlike most quadcopters, which are wider than they are all, the Drone 40 is alien in appearance. The shape of its body, and the name, both refer to the 40mm grenade launcher, a standardized way to hurl an explosive in battle. The Drone 40 can be both hand-tossed or it can be fired as a grenade from a launcher.
Every Drone 40 is battery-powered, and depending on weight and flight time, can be airborne for something between 30 and 60 minutes. At its fastest, the drone can travel nearly 45 mph, and DefendTex claims it can operate at a range of up to 12 miles, far eclipsing the gap in rifle ranges.