Related Clues:

• Spitballs, to class clowns
• Bullets, BBs, and shells
• Ammunition, slangily
• Stuff put into a barrel
• It fills barrels
• Reloading need
• Bullets, shells, etc.
• Spitballs, e.g.
• Fire from a heater?
• Projectiles
• Target practice need
• Rifle filler
• 33-Down supply
• Cannonballs, for example
• Stuff loaded into a barrel