Byrna’s box of two 88g CO2 cartridges are a perfect fit for the Byrna Mission-4. Each cartridge (new) will be good for approximately 60 rounds (or 3x Mission-4 19-round magazines) at full speed. Punctured cartridges within the Mission-4 CO2 buttstock will leak over time.
It is recommended to swap out punctured CO2 cartridges and leave an un-punctured cartridge inside the Mission-4 CO2 buttstock to avoid any compressed gas loss.
88g CO2 Cartridges are only compatible with the Byrna Mission-4 Rifle
*Actual 88g CO2 cartridge brand and packaging may vary depending on availability.