https://codelibrary.amlegal.com/codes/philadelphia/latest/philadelphia_pa/0-0-0-199790#JD_10-821

§ 10-810. Weapons and Dangerous Devices.

 (3) Spring Guns, Air Guns and Bows and Arrows.
  (a) No person shall sell, offer for sale at retail, or use, or possess with intent to use, any air gun, spring gun, or any implement not a firearm which forcefully impels a pellet of any kind.  

  (8) Confiscation. Police officers shall seize and deliver into departmental custody any air gun, air pistol, spring gun, switch blade knife, incendiary paper, contraband weapons, toy or imitation firearm in violation of subsection 10-810(4)

§ 10-811. Penalties.
  (1) Unless otherwise provided, the penalty for violation of any Section of this Chapter is a fine of no less than one hundred fifty dollars ($150) nor more than three hundred dollars ($300) or imprisonment not exceeding ninety (90) days or both.