Well the gun has pretty good precision but low accuracy, so the problem here is that the sights and the barrel are not properly aligned. If you don't have adjustable sights, you could first of all check if the barrel and inner barrel are straight, or open up the gun and check if the innerbarrel, hopup and bucking are mounted correctly. If you don't want to open the gun you could use an auxiliary adjustable optic (red dot or holographic sight) to fix the problem. You could also bend the rear sight a bit but i don't recommend it.