Gun mounts AA capability

To all with the gift of SH4 knowledge......

Is it possible to increase the AA gun capability?
I'm looking at rounds per min increase (shells per min ).
Want to see if it is possible to bring abit of modern flair into the game and simulate the Phalanx or goalkeeper. 4200 rpm.
All i've seen so far is the ability to decrease load times which doesn't really do.

Bellow is a link which will give you an idea to what I am aiming for.

Cheers