Absolutely, in weapon.ini under your weapon it is this command:

ClipSize = 13

It is already there as a parameter all you have to do is specify it. I'm still kind of playing with it only because (dependent on the length of the strafing run and so on, the longer your run the more clips you can specify to fire) so I have mine set to 13, after 13 the jets run out of ammo and can't fire any more. Reply back if needed, I ain't going nowhere