A blow gun includes an ammunition chamber having an internal volume that is large enough to hold at least 30 spherical projectiles, for example plastic BBs. The ammunition chamber has a breath receiving orifice for receiving exhaled breath into the ammunition chamber. A barrel obtrudes from the ammunition chamber. The barrel has a cylindrical bore therethrough, that defines an internal diameter that is greater than the spherical projectile diameter but no greater than 1.7 times the spherical projectile diameter. The ammunition chamber includes a resilient handle portion that is squeezable to displace spherical projectiles within the ammunition chamber.