Its a lightweight powerful springer pistol so it might need some very good technique to get consistent accuracy out of it. It may also be fussy with pellets. Try a lightweight match pellet like RWS Hobby, and clean the barrel first. With the hold, try a variety of grips from holding it lightly to a very firm and see which one gives the best grouping. I have found with pistols that the 'artillery' hold much beloved of the FT springer shooter, where the rifle is held very gently and is allowed to move around during the shot cycle, does not work so well with pistols. You may have to hold on to it fiercely and tame the beast!

Good luck!