Though many shooters swear by the Power Adjusters and stronger hammer springs I must admit I am not a big fan of either of these, especialy with the UK power limits, any PAs that are used on my guns are there for cosmetic reasons only.
One common misconception with these is that the PAs increase power, this is not actually the case as they are intended to reduce and adjust the power to get a performance sweet spot.
How the Power Adjuster does this is to give an external means to adjust the tension on the hammer spring. An aftermarket hammer spring of a different strength can reduce or increase power accordingly.
Now if you add a stronger hammer spring along side the power adjuster this will indeed increase power, albeit this will also increase the bolt pull tension. If too strong a spring is used you will also run the risk of snapping the bolt handle or the valve pin jamming in the CO2 cart necessitating disassembly of the pistol.
In the UK with the Air Pistol 6ft lb power limit I would strongly recommend the use of a Chronograph if venturing down this route as the consequences of owning an over power air pistol are quite severe. In the 2250 and 2260 guns you have a little more room to play with power wise but again always best to have a Chrono handy as the same consequences apply if you go over the 12ft lb limit is an air rifle.
Note that in the UK if the pistol is adjustable via an external or easy to reach means just turning the pistol power down via the PA does not make the pistol legal as the firearms department would just adjust to full power if tested.
