Try this bad boy on for size.
It is a simple LMG, that can fire over 7,200!
It uses the metal storm tube system but it has an auto-loader for it.
The bullets inside the tubes can fire at 1,000,000 rpm in bursts.
Each tube holds 12 bullets.
The gun has 4 settings, safe, burst, slow auto, and fast auto.
Burst is 3 rounds at 1,000,000 rpm, meaning that the 3 bullets are out of the barrel by the time the gun recoils!
Slow auto is 600 rpm (this includes the tube reload time)
Fast auto is... 600 TUBES per minute which equals 7,200 rpm!
The odd looking electronics? Ventilation system so the barrel doesn't melt when firing at fast auto.