it should shoot that low no problem....
What you need to do is take the smallest allen key they give you, and turn the little screw on the upper half of the gun (left side). Once u find this tiny screw hole, use your small allen key and turn it in all the way until it LIGHTLY hits something and you arnt able to turn it anymore without using force. That is the recock screw, you have just turned your recock to 0.
Now, shooting over a chrono, adjust your reg until it is at the desired fps. NOTE: To shoot the gun you have to manually pull back the back block after each shot, because there is no recock. Now, once you have the fps you want, adjust that little screw ******ds until the gun will recock itself and then give it another small turn.
Um all I can say is that my detonator works to 200 fps then the cup seal leakes because it is too low of a pressure.