clearing the MG3 machine gun

[Mike Mercury]

didn't do so in textbook fashion

https://youtu.be/wrkUqOV4kZA

[SnikPlosskin]

What happened there? Hang fire?

[Louie Detroit]

What happened there? Hang fire?

It’s been over 40 years since I messed with a machine gun, but I believe it is because he didn’t close the topcover first.

[Nox]

Open bolt weapon. Hot barrel cook off. Should have waited a minute or so before opening to clear the weapon.

[Burro (He/Haw)]

Open bolt weapon. Hot barrel cook off.
That might as well be in ****ing French for someone like me. :Jeff '79:

[6spdC6]

That might as well be in ****ing French for someone like me. :Jeff '79:


Translated into pipefiitteralease!


Well its a bit more serious than putting a hot piece of slag in your pocket!:D

[ratflinger]

Somewhere there is a Sargent getting ready to apeshit on some troops

[Nox]

That might as well be in ****ing French for someone like me. :Jeff '79:

An MG-3 requires the barrel to be changed under sustained fire every couple of hundred rounds… Hard to believe considering all the movies where they spray an area endlessly. Machine guns fire either on an open bolt or closed bolt. The MG-3 fires on an open bolt, which means technically the breach is open when the round goes off.

So the barrels get red hot under fire. So hot that barrels have been known to melt. So if you have a jam, and a round is still in the chamber, it would be advisable for allowing some cool down before checking on the problem. The round can “cook off” or spontaneously ignite from the heat. Couple that with an open bolt, and you are likely to get hit with some brass in the face.

[VITE1]

I had a cook off with an old 12ga double barrel shotgun. Scary .

[StaticCling]

An MG-3 requires the barrel to be changed under sustained fire every couple of hundred rounds… Hard to believe considering all the movies where they spray an area endlessly. Machine guns fire either on an open bolt or closed bolt. The MG-3 fires on an open bolt, which means technically the breach is open when the round goes off.

So the barrels get red hot under fire. So hot that barrels have been known to melt. So if you have a jam, and a round is still in the chamber, it would be advisable for allowing some cool down before checking on the problem. The round can “cook off” or spontaneously ignite from the heat. Couple that with an open bolt, and you are likely to get hit with some brass in the face.

Correct me if I am wrong, but a GI tactic in WW2 would be to wait for the barrel swap to press an attack. Granted, that was the MG42, but it's basically the same weapon in a different chambering (7.62 NATO vs 8mm Mauser)

[Nox]

Correct me if I am wrong, but a GI tactic in WW2 would be to wait for the barrel swap to press an attack. Granted, that was the MG42, but it's basically the same weapon in a different chambering (7.62 NATO vs 8mm Mauser)

That sounds about right, but I wasn’t around during World War II. I think the MG42 didn’t have a barrel grab handle, so you had to change it with asbestos gloves. We see so much TV where machine gunners conduct sustained fire, but the reality is that experienced machine gunners fire in short bursts. If you fire non-stop for a couple of hundred rounds, you stand the chance of a cook off if not melted barrel. So the question would become, are they changing the barrel out of just giving the gun a rest? Your call.

[JRD77VET]

An MG-3 requires the barrel to be changed under sustained fire every couple of hundred rounds… Hard to believe considering all the movies where they spray an area endlessly. Machine guns fire either on an open bolt or closed bolt. The MG-3 fires on an open bolt, which means technically the breach is open when the round goes off.

So the barrels get red hot under fire. So hot that barrels have been known to melt. So if you have a jam, and a round is still in the chamber, it would be advisable for allowing some cool down before checking on the problem. The round can “cook off” or spontaneously ignite from the heat. Couple that with an open bolt, and you are likely to get hit with some brass in the face.

Thanks for the explanation.

It certainly looked like it cooked off and sprayed hot brass rearward.

[Grey Ghost]

My model 1842 smoothbore .69 will and has done similar, along with Springfields, and Enfields.

After only a few rounds the barrel gets too hot to touch. It will burn your hand. I fashioned a piece of leather around it to hold while loading during reenactments.

We never draw ramrods for safety reasons. The only exception has been at memorial services when we fire 3 rounds. We will draw a cartridge from our box, rip it between our teeth, pour the powder down the barrel, draw ramrod and simulate ramming a ball home. We do ram the paper cartridge portion after pouring the powder.

We had already fired one round and was loading for our second one. I ripped the cart. and poured the powder down the barrel. BOOM!!! Some of the paper must have still been burning from the previous round and it lit off.

We follow strict safety rule about where the end of the barrel is pointed during loading and where your fingers are located. NEVER over the end of the barrel and the barrel never pointed at yours or your partners face.

It embedded several grains of black powder into my index finger (the only one exposed during loading) and gave me a pretty good burn.

I stopped ramming paper and simulating the ramming of a ball after that. That mod. 42 barrel is just too long. Probably a bit safer with the shorter Enfield and Springfield.

[JRD77VET]

An MG-3 requires the barrel to be changed under sustained fire every couple of hundred rounds… Hard to believe considering all the movies where they spray an area endlessly. Machine guns fire either on an open bolt or closed bolt. The MG-3 fires on an open bolt, which means technically the breach is open when the round goes off.

So the barrels get red hot under fire. So hot that barrels have been known to melt. So if you have a jam, and a round is still in the chamber, it would be advisable for allowing some cool down before checking on the problem. The round can “cook off” or spontaneously ignite from the heat. Couple that with an open bolt, and you are likely to get hit with some brass in the face.


Here is a 700 round continuous fire that not only melts the silencer but also towards the end of the video, the barrel and the gas block are red hot.

Suppressor Meltdown! 700 round burst through an M249 SAW! - YouTube

[SnikPlosskin]

Open bolt weapon. Hot barrel cook off. Should have waited a minute or so before opening to clear the weapon.

Holy shit. That’s crazy.

[ZipZap]

That sounds about right, but I wasn’t around during World War II. I think the MG42 didn’t have a barrel grab handle, so you had to change it with asbestos gloves. We see so much TV where machine gunners conduct sustained fire, but the reality is that experienced machine gunners fire in short bursts. If you fire non-stop for a couple of hundred rounds, you stand the chance of a cook off if not melted barrel. So the question would become, are they changing the barrel out of just giving the gun a rest? Your call.

Thus, the 3 spot...

[Stevedore]

In my engineering career, I did some finite element heat transfer analysis relating to the likelihood of cookoff in a specific weapon system. Scary stuff, if you're not aware of the possibility.