Another thing is to get it serviced by an Angel tech to clean out any crap and put new perishables in. It'll save the FPS going up and down and generally make the marker run better and so shoot more consistently. If you know what's coming out of the end of your barrel each shot then you yourself can be accurate.
I used to have issues with my Speed 04 but that was because of spikes in output.
Tom Allen is your man if you want it serviced, uber Angel Tech.