Is this fast enough? "Only" about 300 rounds per minute, but no real difference from full auto in effectiveness.
Until the barrel melts because it's not made to fire like that for long. Of course, you didn't know that, did you?
and the gun will malfunction before the barrel melts
Really?
I wonder why that didn't happen in Vegas when Paduch killed 50 and shot 500
See, this is why you're on ignore. The Vegas shooter had 23 rifles. He did not fire 500 rounds through one rifle. All you had to do was google Las Vegas shooter and you wouldn't have made a fool of yourself. Try harder.