My Items Can Upgrade

Yang Yuan transmigrates into a world full of powerful beasts and monsters. And he is chasing by a huge wolf. At the very moment, he finds he could see information about his handgun and update it just because he dissembled and resembled it.
[Handgun Lv.1: 0/5 (Ordinary Handgun)]
Firing a shot increases by one point of experience, leveling up doubles the range, eventually the bullet can produce an explosive effect.
Disassemble the four legs and shell of the small turtle, reassemble them:
[Turtle Lv.1: 0/5 (Ordinary Turtle)]
Leveling up doubles the size, eventually becoming a Mountain and Sea Giant Turtle!