no, like... biological agents can create quite some carbon dioxide at high pressure so if at the factory a melasse together with bacteria would be encased in stead of propellant, and then the heat of the engine could an hour or so before battle prime the bullet (heat makes the bacteria eat the melasse, they fart and create pressure, this generates more heat and that generates more bacteria farting) once the bacteria have the pressure so high that they sterilize themselves the bullet is ready to fire compare it to a potato gun
