Related Clues:

• Pistol pop
• Capper
• Pow!
• Range report
• Last act
• Slam sound
• Screen-door sound
• See 109 Down
• Big report
• Drum sound
• Explosive noise
• Exclamation point, to printers
• Epilogue or coda
• The launch of fifty fireworks in the span of a minute, say
• Theoretical "big" event