Your input in the tank should be 200PSI or more over your operating pressure. A low pressure tank that outputs 450PSI on a marker running at 350PSI may get shootdown, but one running at 250PSI probably wont. A HP output is still a good idea, regardless.
My STO is sweetspotted at 285PSI out of the inline reg and is +/- 1 over a chrono getting around seven pods on a 68/45 fill.
I never had too great of luck running them over 300. They started to ping and act over pressurized, however, I might have just gotten oddball valve, chamber, and spring combinations.
A gauge on the underside of the front block is your best friend, and it will really help you understand what's going on in the valve chamber.
Sweetspot it, see where it's at pressure wise, and that's your golden operating pressure. It's surprising the variations that are "right" as far as operating pressure. There are a ton of variables there with the springs, hammer weight, cocking rod weight, and valve constructions.
Last edited by Dk-79 : 04-09-2014 at 02:13 PM.