Not following you, rounds per minute is how it's usually expressed and M16s are commonly rated at 700-850 rpm
I believe the quibble is the difference between the cyclic rate and the effective rate, that is, how quickly the average soldier can swap magazines and sustain fire.
Close, but not quite. The 700-900 rounds per minute is the rated cyclic rate of an M16/M4. That is how fast the bolt moves. The gun can't fire that fast without destroying itself. It's not a matter of how fast someone can swap mags (which is it's own subject) but rather what the weapon is capable of without destroying itself. If you put a Hollywood endless mag in an M4 , flipped it to auto, and held the trigger back, the gun physically couldn't fire 700rds in a minute.
It seems like a quibble amongst gun folks because we understand the difference between cyclic rate and rate of fire, but the idiots that wrote that article actually believe an M16 can fire 700 rounds in a minute. It can't. It'll literally melt first.
For Example:
https://www.youtube.com/watch?v=BSizVpfqFtw 830 rounds in 6 minutes killed the gun.
For the record, per TM 9-1005-319-10, the max sustained rate of fire for an M16/M4 is
12-15 rounds per minute. Max Effective RoF of an M4 in Auto is 90rpm.