Because the cannon is useless. It's only there because every time you point out it's useless people start yammering about the F-4, a plane that came out five d

Because the cannon is useless. It's only there because every time you point out it's useless people start yammering about the F-4, a plane that came out five decades ago. Even when the gun is working, the A version is only going to have 120 rounds. Which is three seconds worth of ammo.