Not sure if this is known within the already known audio issues, but extended firing of LMGs is off. First, the sounds/vibrations don't seem to match up. Not sure exactly what, but it feels strange. Also, the vibration will often cut out and audio continue (just while firing, audio does not continue when not actually firing, like in the beta).

This is when holding the trigger for continued fire on belt-fed LMGs. Haven't tried a mag-fed one.