Pochari Technologies has developed a new type of modular submachine gun. The weapon uses a new in-house developed round with a varying length cartridge casing and varying mass bullet depending on whether long-range or sort range operation is desired. The rounds are of the same diameter as to allow the weapon to be fully modular. Full auto fire rates in excess of 1500 rounds per minute are achievable thanks to the piezoelectric firing system. Piezoelectric crystals based on the reverse piezo effect provide high actuation force at very high velocities and are extensively used in the most demanding applications such as high pressure diesel injectors to provide up to five sprays per combustion cycle. The power density of the actuator is very high and adds little to no additional weight over a gas fired system but provides a significant reduction in mechanical complexity and chance of failure. Liquid cooling allows the user to operate the weapon at 1500 rpm for extended periods of time without worrying about barrel warpage due to excessive temperature buildup. The piezoelectric firing systems provides a variable rate of fire, depending on the pressure on the trigger, the rate of fire varies from 100-1500 rpm. A backpack fuel cell power supply provides the electrical current to the piezoelectric crystals and provides pumping power and recycling and active cooling for the glycol cooling system. The magazine is styled after the FN P90 to maximum capacity but with the absence of a 90-degree turn system, allowing for faster fire rates and less mechanical complexity. The weapon can convert from compact submachine gun to long-range rifle and back with simple removal of the barrel module. The weapon is constructed primarily of carbon fiber with the exception of the barrel and firing system. Pochari Technologies’s founder Christophe Pochari plans on manufacturing a prototype of this weapon as soon as funds allow. A 3D CAD model has been developed. The weapon is ideal for high-intensity to low-intensity urban combat in the digitalized battlefield where fuel cell backpack power is critical for mission success. This weapon is also ideal for special forces and law enforcement. The fuel cell is a high-temperature proton exchange membrane using a micro reformer to crack synthetic diesel fuel into hydrogen. Pochari Technologies plans on developing boron based propellants based on nitro substituted borazene, borazine, iminoborane and azaboridine. These boron based explosives display much higher detonation velocity, CJ pressure and cylinder expansion energy than comparable all carbon based materials at corresponding densities.