[spaghetti]

Do you shoot above or under the fish? And wich is the gun model? This would be interesting.
However, dont' loose your temper. Unaccuracy with pneumatics can be related to unnoticed gear "accidents": shaft bent during loading, floppers "curled", line too thick. Check these, than focus on your aiming techinique: dont' look at the shaft, just look at the fish as you probably used to do with band guns. But before this, train your hand to "cover" the view of the barrel with rear of the handle (more simply: the rear of the handle has to precisely "cover" the barrel from your sight: this way airguns shoot straight, and not too high. It's the opposite of bandguns, that must shoot slightly muzzle-up).
hope this helps