Over heating
The Firearm Blog: The truth behind the recent M4 controversy. He notes:
In fact, it is not even possible that an M4 barrel can heat up to the point of being white hot. M4 barrels are made from Alloy Steel 4150. The melting point of this steel is 1426 degrees Celsius. For steel to go white, it needs to be over 1400 degrees Celsius.
Seems it wasn’t the M4s overheating but the SAW. Which tends to happen.
October 13th, 2009 at 11:23 am
Heh. I noted the same problem on Bullshido, then someone else noted that the M4 is a 3-shot-burst weapon anyway.
I figured it was one of those harmless rhetorical flourishes reporters are so fond of, probably written by a reporter who doesn’t really know why gun barrels get hot or what “white hot” actually means.
I’ve had carbon steel up to a yellow that was pretty whitish in a charcoal forge, and at that point, carbon is literally shooting out of the steel in bright yellow sparks. It looks like it’s a burning firework, and the metal flows like warm butter. It’s a welding heat. It would make a particularly horrible explosion if a rifle were fired with the chamber and barrel at that heat . . . .
October 13th, 2009 at 1:19 pm
I’m sure with several 100 round drum mags you could get the M4 to catch fire! AKs can do that,so I have no doubt M4s. Melt? Maybe, I dunno how hot, say, 500 rounds in 60 seconds would make a M4!
But the M4 is not a water cooled machinegun and from the news it sounded like they were spraying-n-praying and not aiming!
October 13th, 2009 at 2:12 pm
I dont think you could get 500 rounds through a M4 in one minute, even on burst fire. But I’ve never fired a weap that has 3 round burst so I cant say for sure. And since the standard combat ammo load is 180 rounds…
I have used a M16A1 when I was in the NG and on full auto with 5-10 round busrts I never had my weap seriously overheat. It did get REAL warm, but it never got to the point where I had to worry about a round cooking off in the chamber. And the barrels on the M16A1 have thinner walls than the M4.
Those guys who were there are combat veterens who know what they’re doing so I have no doubt that there were problems with the weaps. There also could’ve been some other factor that was affecting the rifles that was’nt mentioned.
October 13th, 2009 at 3:00 pm
M4A1 is full auto, not burst.
October 13th, 2009 at 4:19 pm
If Wikipedia is to be believed, ben, the M4A1 is used by special operations and is not general issue. The M4 (not A1), M16A2, and M16A4 are semiauto and burst-only. The M16A3 is/was used by the Navy, and the M16A1 should be nearly out of circulation in the US military.
October 13th, 2009 at 7:05 pm
Remember that marines aren’t metallurgists. They aren’t going to be aware that white hot metal would be liquid at that temperature.
Much more likely that whatever coating was put on the barrel during manufacture began to cook off and turn white.
October 13th, 2009 at 7:40 pm
I use the M4A14 myself. It’s a belt-fed, with a cyclic rate of 1200rpm and it’s equipped with a state-of-the-art, titanium, combat skillet for emergency, combat pancake making. Spray and pray isn’t that practical, but spray and cook heats up the skillet real good and makes those pancakes a nice golden brown. Confuses the enemy too! They don’t know whether to shoot me, or stop and have some pancakes. Why, it’s so unfair, that it’s technically against the Geneva Convention. Ya wanna pour a little Aunt Jemima on those pancakes, Mr. Taliban man? It’s a highly effective combat system. No shit!
October 13th, 2009 at 8:31 pm
Don’t care why, If their weapons are failing they need some thing better or need to have backups ready to go and quickly available.
October 13th, 2009 at 9:52 pm
A marine I work with who was an MG sgt has a story of an M2 hot enough to see the tracers lighting off in the barrel. But that’s an entirely different kettle of fish.
(IIRC in a Sandbox furball – but he made it to both the Sandobx and the Rockpile as well as a stint in Kosovo).
October 13th, 2009 at 10:31 pm
I thought it was an Army fight, what are you talking about Marines for?
October 13th, 2009 at 11:33 pm
seriously overheated barrels will droop well before they melt.
October 14th, 2009 at 7:29 am
Cause it was a “hot gun” story? I did mention it wasn’t directly relevant