@Pfddi you can ask STO to try another core with your Falx. I did compared standard and moderate cores and kept moderate. I think it is extra $60 if you decide to keep new core. And yes, my .25 krait also much quieter below 850. That's where I decided to stop, 850. Enough air in my small bottle for 4 mags.
@adknives - Unfortunatley, this is a special Falx they sell without the choice of flows for lower power 177 and 22s. I just got greedy and turned it up!
@Silent shot - Remember to always degass the gun if you intend to reduce the plenum pressure! I learned that the hard ($) way! And also do small pressure increments with small hammer spring increments. Small turns go a long way on a Krait!