I read somewhere that one of the drawbacks of the MG-42 was that it shot so fast that it wore the barrel out really fast and that the squad with one usually carried several.
But what exactly does it mean by that? I’m not too familiar with guns in general, so does that mean it won’t shoot bullets anymore once the barrel wore out?
Also, since it ran through ammo so fast, how many rounds did the squads carry at one time?
All air cooled MG’s suffer from the same problem and most will have a quick-change barrel to eleviate the problem. So it is not a problem specific to the MG.42.
Basically what happens is that as the metal heats up it gets softer and the bullet passing through the bore wears the rifling down faster. Also accuracy suffers but that is less of a problem on a MG.
I was talking to a Vietnam Vet once that manned a Browning .50 during an attack by the North Vietnamese Army, he said that he kept on shooting until the barrel was glowing red from the heat. He knew it wasn’t good for the gun and not proper proceedure but there was no break in the attack.
does this same problem apply to mortar tubes?
I’ve never fired a mortar before so I can only give my opinion; but I’d imangine that it is much less of an issue for them. Since the rate of fire is alot lower and there is less friction as the projectile passes down then out the barrel / tube.
That said, since there is heat generated by the charge going off. I would guess they do warm up. Just not enough to be glowing.
The barrel heating problem was originaly dealt with by enclosing the barrel in a water tank. Those are the big fat MG you see in WWI. Some water cooled models were still in use in WWII. Since these were so heavy they were limited in mobility. Usually used for sustained long range fires. Their advantage was they could put out a high volume of sustained fire.
Some other problems of overheating a MG:
Hot chamber prematurely fires a cartidge. Result is a jamed cartridge case & possible broken extractor hook.
Overheating metals cause parts of the bolt & feed mechanism to break. Result is janned bolt or feed. Worst, in rare cases the reciever flies apart and the gunners are injured.
Many light MG like the Lewis Gun or the BREN gun did not have quick change barrels. They depended on a slow cyclic rate of fire and crew training to prevent overheating. All machinegunners are trained to fire short bursts & then to pause a few seconds. This helps keep the temperature down, and it allowes the gunner to corect the aim. Unless the gun is tightly held down the muzzle will climb, and the bipod or tripod will vibarte and shift the aim.
The BREN barrel couldt be changed in seconds -
Only guns firing from a closed bolt suffer from “cook-off” and even then it is still following it’s normal function; fire, extract spent case, reload and fire. I fail to see how that could cause jamming.
All that aside it is for this reason that most automatic weapons fire from an open bolt.
I should add that the Germans did have one additional heat related problem not encountered by the Allies, and that was the use of laquered steel case ammo. As the barrel heated up the laquer would melt and stick to the inside of the chamber causing extraction failures.
According to one account I read, an experienced MG crew always kept a tin of brass cased ammo aside when they could.
Correct, it even had a handle attached so that you wouldn’t burn your hands in the process.
How much ammo depended on what the units was doing, and what sort of squad was carrying the gun.
A German rifle squad in the attack might start with 500 rounds carried by the gunner and his assitant. Some of the other squad members might carry 100 or 200 rounds each, on a loose belt, or still in the package.
A crew with a tripod mounted MG 34 or MG 42 could have two, three or even four thousand rounds at hand. The tripod mounted gun was susposed to have a larger crew of 3-4 men. There were often men detailed to do nothing but carry ammo forward from the supply wagons.
The typical German rifle battalion or regiment had some horse drawn carts following with several thousand rounds of ammo. If a motorized unit the trucks or halftracks would have as much extra as possible distributed amoung them.
In a well prepared defensive position ten thousand rounds might be near at hand for the use of the MG. In those sort of situations two or more MG would be positioned near each other sharing a common ammo reserve.
Some can be fired to the point where the propellant charge will prematurely ignite from excess heat. Basiclly the charge fires only part way down the tube and the projectile falls far short.
The howitzers I trained with could be overheated with rapid and sustained fire. In training we never came remotely close to this occuring. In combat it occasionally happens during battles where the mortars or artillery fires continually for hours.
I’m just drawing rom combat experinced guners testimony. I did have many others, instructors & whatnot, tell me the same as you that the gun will cycle normally. However others who did fire their MG untill overheated desciribed the round cooking off before it was seated in the chamber and the bolt closed. The end result was the cycle interrupted and brass in the chamber or feed. Originaly I thought this something pecular to the US M60 MG. But a older vet refered to it happening with a Browning MG.
IIRC the Browning, uses a Maxim style lock and was originally designed as a water cooled MG and it fires from a closed bolt.
Don’t get me wrong, cook-off’s can and do occur. And where they are dangerious is that you loose control of the MG because it will keep running until the supply of ammo runs out.
The other issue you describe is an out of battery discharge, where the gun goes off before the chamber is properly locked. This is a dangerious situation as you will get burning powder escaping into the receiver (I think there was a design flaw which made this prevelant with the MG.42). But since the reload cycle is so fast I find it hard to see how it could occur from heat alone.
Did the MG-34 also encounter the same barrel problems? And are parts from an MG-34 compatible with an MG-42?
Like I said, over heating barrels is a common problem in all air cooled automatic weapons (actually its a problem for water cooled ones too if you don’t keep replacing the water) so yes it affected the MG.34 too.
No there are no interchangeable parts between the MG.34 and MG.42
The most dangerous thing that can happen with an air cooled machine gun is if you get a stoppage in which the cartridge is almost fully chambered, but the breech mechanism is not locked. A cook off at this point is nasty and results in a breech explosion.
Thats probably the event the vets were describing to me.
To change the subject just a hair has anyone here ever witnessed a barrel improperly locked in after a change fly down range? I’ve heard of it third hand, but never from a reliable source.
This is one that would need several barrel changes for sure !
MG-42V/MG-45, roller delayed blow back system, rate of fire 1350-1500 dpm.
I have a semi-auto version of the MG-42, and barrel change is very easy and fast. even though its semi-auto, it is quite easy to get a good 250 rounds through the barrel. as barrels are rare and expensive, i baby them!
forgive if this is a dupe:
“…(4) To change barrels.—(a) General.—The barrel on this gun should be changed after firing 250 rounds in full-automatic fire, or, in cases of emergency, after firing 400 rounds. Spare barrels are regular equipment with the M.G. 42 and are carried in either single- or double-barreled containers by the gun crew. The single-barreled container opens up so that the hot barrel can be laid on it and exposed to the air to facilitate cooling…”
(source: http://www.lonesentry.com/manuals/german-infantry-weapons/mg42-machine-gun.html)
Thank God for Asbestos Gloves! so what do they use now??? 