The Volcanic cartridge was basically a Minié ball with its base cavity filled with propellant. A paper disc holding a fulminate pellet closed off the back of the cartridge. The ignition system was similar in concept to the needle fire system, but it did not require the long, easily damaged firing pin. The cartridges were underpowered and the gas seal was inefficient, but the Volcanic repeating rifle could hold a large quantity of ammunition in its under-barrel tubular magazine.
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