Nilxo12

I use propane for my mws and plan on using propane aswell for the mp7 as i dont see the point having two different gas if they both can take it. MP7 is shooting relatively hot 1.14j (1joule limit) most npas i see are for VFC or KWA, is there anyway of reducing the fps on a TM MP7? I was wondering if trimming the rocket valve spring would help?