Manually operated , or it can only fire one at a time , it fires all 40 mm grenades , less-deadly and non-deadly ammunition ( or what a gun fires ) , and tear\/irritant gas capsules ( the container in a liquid or gas is stored ) ; spent ammunition is ejected for easier reloading . Manually operated , it fires all 40 mm grenades , less-lethal and non-lethal ammunition , and tear\/irritant gas projectiles ; spent cartridges are ejected for easier reloading .