In stock form, the gun isn't suppose to be reactive, so your is probably working exactly as it should.
You can make it more reactive by adjusting one or more of the following parameters:
1) increase the pressure coming from the tank regulator
2) shorten the on-off pin
3) lower the require chamber pressure (Use an optimum length barrel and the shortest gold bolt spring.)
You can add a couple of shims in between the on-off halves so simulate a shorter pin without having to modify yours or buy a new one.
Except for the Automag in front, its usually the man behind the equipment that counts.