Question on the size difference of the FX 480 vs 580 air tanks

Im going to highly assume that the extra capacity in the 580 comes from it being longer, and not larger in diameter because then it would affect other aftermarket add on’s Like extended picatinny rails, bipod clamps, etc. Can someone verify if my assumption is correct? For all I know it could be a bit larger in diameter just enough to miss the barrel shroud, and also longer, so that’s why I need someone to verify. 



Thank you!
 
500cc @300 bar will put out around 7 times as much.

I used the Tank Fill Calculator at Airguns Of Arizona. 
A hypothetical tank of 75 cu/ft @4500psi, would fill an empty 500cc bottle to 4351 psi (300 bar) .5 times and would fill an empty 580cc bottle to 3481 psi (240 bar) 3.5 times.
3.5 / .5 = 7

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