you know, a .22lr bolt action for $250 and a large supply of CB shorts is dam near as quiet as a pellet gun and gives you 750fps with a 30 grain bullet. i use mine in my backyard all the time (in a rural area with neighbours) and you can't tell the difference between it and my CO2 pistol. food for thought.
i don't understand the yearning for pellet guns that are just trying to be .22lr's... they are no quieter than a cb short, far less versatile, more expensive, and heavier... for $100 more you could have a marlin 39a and cycle 18 or so cb shorts out the barrel in a few seconds. any other .22lr can still be used as a single shot quicker than a pellet gun.