8 Gram CO2 Cartridges are only compatible with the Byrna HD and Byrna SD.
Our box of ten 8g CO2 cartridges are custom fit for the Byrna SD and HD Launchers. Each cartridge (new) will be good for 15-20 rounds (4 mags in a 5 round magazine) at full speed. Punctured cartridges within the Byrna HD will leak over time.
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.