The Byrna HD will puncture and fire the first round at the same 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.70 Shipping LxWxH: 4. Byrna 12 Gram CO2 Cartridges 10 Pack XL SD w Boost.Attributes Custom fit for the Byrna HD with Byrna Boost 12G adaptor Increases shot capaicty to 30 rounds per cartridge More Information Color: Silver Primary Color: Silver Material: Steel Country of Origin: China Unit of Measure: EA International Restrictions: YES Item LxWxH: 4.