[Mr V]

If you go to the link Mr Forbes provided you'll find another tab labeled refill rates. Of course those are only valid with the listed sizes and pressure ranges. Of course the listed pressure ranges are not exactly what we see in FRC and it is unlikely that you are using a .5 gallon tank. However you could probably use that data along with the CFM at the different pressures to derive how it would work with your tank size and pressure range.

The thing to keep in mind is that it is a piston type compressor. That piston has a set volume however you don't get to use all of that volume with each stroke. At zero psi the entire volume of the cylinder is discharged. As the pressure rises the initial portion of the stroke is used to reach the current tank pressure and no air flows out of the cylinder until the current pressure is met. The other thing is that at zero psi there is minimal load on the compressor's motor. As the pressure rises the load on the motor increases so it's rpm decreases. Not that the chart lists different current consumption at different pressures to reflect that change in load and rpm of the motor.

The listed CFM in the chart is what flows out of the compressor when working against a given pressure but the air does cool and contract when it reaches the tank further complicating the calculations.