[Sgt.Hartman]

mmmm In that kind of electric motor set up, the ma WILL affect the rate of fire,
it would not be affected if airsoft gun would be equiped with speed controler, witch is not. volt X A= watt
mA = .001 A
the ROF will be determined by the number of watt your battery can give, the quality of the motor part and the restriction, (in this case, the spring but there is also the quality of the shimming and the ratio of the gears).

it is a bit true that higher Ma will give you a better longevity in airsoft gun(specially if you compare a really low A battery with a high one, but not as a RC car where there is a speed control.
you have a stock gun, witch mean the spring is pretty easy to compress, no need for a 9.6V 3000 mA.
my advice 8.4V 800mA to 1500mA is perfect.