Ya, longer dwell makes you quieter, but also uses more air.
Each time you change your dwell, you should readjust your regs as well.
If you want the smoothest shot possible, then you'll also want to run your LPR as low as possible. Just set your velocity, then turn your LPR down until it's at the lowest setting it can run at consistently under rapid fire.
ETEK 3LT, with 14" Ti boomstick and cure 3 + bolt F/S
Vanguard creed eyes, membrane, bolt pin, detents, gaskets, schraders, orings and more F/s[/color]
Old school angel poppets/cup seals(LCD and A4/speed), spring detents(not sure which models) F/S