homemade gas system physics help

[stealthyjawa]

I am trying to build an hpa powered airsoft gun and have ran into a problem:
Is there a way to calculate the speed of air flowing through a curved pipe? Eventually a closed straight pipe and a closed curved pipe (with equal volume) will reach the same pressure if x amount of gas is added to the system, but will the rate of pressure change be different? or will it be small enough that there is no discernible difference in fill rate?

This is an attempt to plan out a system that fires from a closed bolt (feeding nozzle) but uses the same source of air for reopening the bolt.

[Apotheosis]

There shouldn't be any noticeable differences, especially since the piping you will most likely use for this will be of a fairly small diameter compared the the pressures you might use.

[stealthyjawa]

It would probably be under 200 psi...

[Apotheosis]

How big of a diameter pipe are you planning on using? 200 would be plenty depending on the pipe size.