ok well im gonna try to answer every question I can but if I miss one feel free to ask again...ok first off, not sure how many pumps it takes to fill it haha... lets just say im pricing scuba tanks... filling it to 2,000psi not sure how accurate it is but when I had it hooked to co2 it would one hole at 30 yards so I would imagine it will not loose accuracy just gain range...as for power I don't have access to a chroni but I would say GGDT was right when it said about 1,000 fps with a 180gr bullet