It seem in Star Trek a ship phaser/energy weapons have a maximum range of 300,000km, Photon Torpedo have a maximum range of 3,000,000km and Quantum Torpedo have a maximum range of 4,050,000km. There is no size difference between Photon Torpedo and Quantum Torpedo. Federation ships just have less Quantum Torpedoes than Photon Torpedoes because of the complexities involved with the manufacturing of Quantum Torpedoes. But as always canon information should be taken in context with a view to game mechanics.
