On the MK23 platform, you have 4 main variables that affect the power output: inner barrel length gas strength (or HPA) hammer spring strength nozzle set (only to reduce output) The first thing you can do, is to increase the barrel length. This will boost the power usually from around 1J to 1.5J on green gas. You can also use stronger gas to increase power output, however, the original hammer spring in SSX23 / MK23 is too weak to overcome the pressure and open the valve. Therefore you will need to use a stronger hammer spring if you want to make use of stronger gas. You can either purchase SSX303 Trigger Assembly that comes with stronger spring or you can purchase our hammer spring set and upgrade it yourself. And lastly, if you've increased the power output too much and wish to fine tune it (this only works by reducing it) you can get yourself SSX Nozzle Set by Novritsch to limit the gas output power.