(adsbygoogle = window.adsbygoogle || []).push({}); You need a Turbo/rapid fire controller with turbo button so you can choose wich button is tapped rapidly. This is tested only with PS3.

Create a class with a semi-auto weapon(G3 for example). Set turbo to square and triangle. First press square-button. Keep pressing it and start holding triangle-button. Keep pressing both buttons and start pressing R1-button. If you did it correctly you should now shoot unlimited amounts of ammo that doesn't hurt anyone.
(Sorry if this is old)

ahh man i wanted to know how to do this with out rapid fire controller but ohs well

Hold the fire button and reload button at the same time and keep pressing your switch weapon button.

im pretty sure nobody else can even see the bullets

So u Shoot Blanks then?

You shoot blanks and no one even sees the bullets not even a spectator. You can also shoot turbo blanks with M40A3 and R700: Shoot a few shots then start pressing square while reloading start pressing triangle and after that press R1.