Related Clues:

• Metal-shell filling
• Boom cause
• Contents of some shells
• Component of the explosive Torpex
• Cause of some blowups
• Implosion material
• Boomsticks?
• Hit for 1-Across
• Blowup source, perhaps
• Quarry compound
• Cause of smithereens, maybe
• Block buster?
• Blaster's stuff
• It blasts
• Big bang cause, briefly