[jamuke]

as long as it's for a Marui hi capa,

if you're thinking of upgrading of your blowback unit to a lightweight one then the piston head is part of the package so you wouldn't need another

the Airsoft surgeon one for sale I linked with the upgraded loading nozzle is not a bad deal as eventually you'll need a new loading nozzle

of course the nine ball is aluminum and slick looking

regardless ...
remember to lube your O-rings, if you put silicone oil in your propane you should get enough lube but I also like to add a little extra when I clean my pistols.

I recently purchased silicone grease and spent the day greasing O-rings on everything I've got

anyway enjoy your pistol, GBB take some getting used to as they take effort to maintain but I find that to be part of the fun

as for making your gun work properly well..it should fix your gas consumption problem