In modern systems, this is almost always a percussion cap.
She doesn't need it with that percussion cap, so you are holding a live thing in your hands right now.
The hammer would strike a percussion cap, setting off the explosive.
By the time of the civil war, nearly all guns manufactured used the percussion cap.
He had the packet of percussion caps in his pocket.
It was in common use before the introduction of percussion caps.
The hammer had not struck the percussion cap of the cartridge.
They are designed for use with a percussion cap and lead shot, without gunpowder.
Electric match and percussion cap are the most common ones.
The little thing would be blown out like a percussion cap!