Any object, such as a rock, stick, shoe or butterknife used as an emergency or field-expedient tool. From the old TV series "Then Came Bronson" when Bronson (Michael Parks) uses a rock to pound dents out of his bike's fender and gas tank.
That guy can fix anything with a Bronson rock and a smokewrench
An improvised grenade made of a shotgun shell inserted into a length of tubing (cardboard, plastic, or thin aluminum) with fins attached to the other end, and a marble or ball bearing taped over the primer. The nut buster is thrown into the air and lands on the marble, firing the shell and spraying the area with shot.
During the riot, two men threw nut busters into the crowd