Looking for actual temps. Not full-auto, not mag dumps either. Let’s say semi with a firing tempo one might encounter during a carbine course (not just casual plinking).
ABNAK,
These pictures were taken after emptying 2 magazines (28 rounds each) at a rate of fire of about one round every 2-4 seconds. I was doing some testing on my pencil barrel to discover POI shift from cold bore to heated barrel. Yeah it wasn’t a class with faster and longer strings but thought this may help. Interestingly the hottest I’ve ever measured one was on a converted belt fed AR. Measured 417° at the gas block.
-Jax
I’m surprised that’s it. I’ve gotten Mosins to smoke on numerous occasions, but have no clue how hot that was.
Heck I put enough rounds through a Garand one afternoon that oil was bubbling out of the wood. 
My buddy’s site but me holding the rifle.
-Jax
I didn’t know that was possiable. Crazy
jaxman7,
Thanks for the info! I thought the temps would’ve been much higher than that, especially on the belt-fed.
See the document at the link below. It’s old, but it’s real data. For the quick and dirty answers, start at pages 8-10.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA019649
Joe Mamma
It’s amusing to see an official military report refer to 20rd clips. I’m surprised how jagged the line is in Figure 10 (page 29 of the pdf), it’s a mag dump every 10 seconds but has steps at about half a second. Thanks for the link, it’s worth going through.
Figure 10’s description states it is firing sequence #5 or 20 rounds over 10 seconds in full auto.
That means one two rounds burst each second, which is not hard to do…pull the trigger then let off immediately, then count “one thousand-one”, repeat…
But, I think it was a thirty round magazine, as there are 15 steps in 15 seconds and no pause in the heating to account for switching magazines.
Each jump is a two round burst, the down slope after each jump is the barrel cooling off between bursts. From that you can estimate the maximum rate of fire that will keep your barrel very near ambient (about one round every 6 seconds).
What I’m surprised at is the sharp angles, I would have expected the same overall shape but a smoother curve.
There’s also a 20rd every 20 seconds that they say is full auto, I wonder what they mean by that.
They mean that they fired it in full automatic in such a way that they averaged 20 rounds every twenty seconds…