Long sessions: rounds cooking off

[iakdrago]

After a long therapeutic range session, the barrel of my gun got extremely hot. For piece of mind, considering where the gun is pointing when it's in the holster, i decided not to chamber a round. Could someone with some knowledge on the issue comment on the possibility of the chambered round cooking off after a voluminous rapid fire session.

[JodyH]

In a handgun it's not going to happen, not enough heat generated and not enough metal to heat soak.
I've seen a Glock hot enough to melt the guide rod, melt the nylon insert out of a Big Dot front sight and cause the dust cover to droop noticeably (1000 rounds in under 14 minutes).
No cook off at anytime.

Rifles are a whole other ball game.

[secondstoryguy]

While theoretically possible, it's not going to happen under any normal range conditions. Modern propellants and primers are extremely resistant to cookoff.
I know it's not hard evidence, but here's a guy firing 1000 rounds without stopping out of a Glock: http://www.youtube.com/watch?v=0_JuF23qazI

[TGS]

And even in rifles, it's one of those things that most people have never seen.

One of HK's previous sales demos for the HK21 7.62 machine gun involved shooting 1000 rounds continuous (one long belt), followed by a semi-auto accuracy test. It's a closed bolt weapon. It did not result in cook offs.

[JodyH]

I've seen one cook off in a suppressed M4 carbine.
It was after several hundred rounds of continuous fire and it happened almost immediately after the shooter stopped midway through a mag.
Suppressed AR's can and will get HOT.
The suppressor was so hot the paint burned off and the barrel of the rifle became "chalky" looking.

[TGS]

I've seen one cook off in a suppressed M4 carbine.
It was after several hundred rounds of continuous fire and it happened almost immediately after the shooter stopped midway through a mag.
Suppressed AR's can and will get HOT.
The suppressor was so hot the paint burned off and the barrel of the rifle became "chalky" looking.

I imagine an M4 can get very hot, very easily. Enter the tales of gas tubes melting during the Battle of Wanat.

[WDW]

I've only ever seen it with machine guns & even then its a lot of full auto w/out barrel changes before that happens.