[Q
No. It is not. The barrel of an AK-47 gets so hot after about two magazines, I burned my hand THROUGH a leather glove when I accidentally grabbed the barrel in the dark.
Two quick 30 rd mag dumps in a full auto M-16 will heat up the barrel pretty much.
I know some people have done it in a test but 23 straight magazines (which would take several minutes) would pretty much burn up a barrel and probably even melt the hand guard.
So why do the manufacturers use that number in their specks?
They are just quoting a cycling rate.
If there was a continuous feed of ammo a full auto M-16 would cycle through 600-700 rds in a minute. The only way it would have continuous feed is if was belt fed. 700 rds in one minute would burn the barrel up. The temperature of the barrel would probably approach 900 F.
An AR-15 cycle rate is dependent upon how many times per minute someone can pull the trigger. There are some gimmick things out that that will mimic F-A fire but they are not very good.
The cycle rate is meaningless because the real rate is limited by magazine capacity. The standard mag is 30 rds. You buy some 100 rd drums but they are heavy and are prone to jam..