BYRNA 12G CO2 CARTRIDGES ARE A CUSTOM FIT FOR THE BYRNA HD WITH THE BYRNA BOOST 12G ADAPTOR. BYRNA 12G CO2 CARTRIDGES INCREASE SHOT CAPACITY TO 30 ROUNDS PER CARTRIDGE.
It is recommended to swap out punctured CO2 cartridges and leave an un-punctured cartridge inside the Byrna HD to avoid any compressed air loss. The Byrna HD will puncture and fire the first round at the same time.