Burning Out Machine Gun Barrels

After bombarding Henderson Field, would the Japanese guns still be accurate? Maybe the bombardment ammo was less hard on the liners?

 

It's funny you mention that. In a book called 'Guadalcanal: The First Offensive' by John Miller Jr., it says that the Japanese fired 918 360 mm rounds at Henderson on Oct 13. 625 AP and 293 HE. That doesn't make any sense to me, unless they were short of HE ammo. I assume the AP would be harder on the bore, but I don't know.

I've been meaning to ask if anyone knows why they would shell Henderson with AP rounds ever since I read it in that book a year ago

 

They go into it in some length here:
http://www.navweaps.com/Weapons/WNUS_16-50_mk7.htm
The short answer is "it depends".

 

Good stuff there...Ah, the "Swedish additive". I use something similar, with the Swedish milker purchased on ebay...And always heard about Atomic Annie land based nuke artillery. Never heard/thought about the Mark 23 "Katie" nukes for the battleships.

 

Have seen some mighty quick barrel changes on M60s (my favourite weapon) in Vietnam footage of battles...Gunner and his mate had them strapped to their backs...the gunner calls for a new one whilst hes still firing the old...
Gatling or mini-guns should now make more sense to people...

 

H. Severloh (the beast of Omaha Beach) who fired 12,000 rounds from his mg-42 and might have killed up to 1,500 americans, had two spare barrels. The barrel would ignite the grass fronting his gun. He timed his firing with each landing craft that dislodged troops and waited for the soldiers to wade in water chest deep, where they were helpless.

 

i read that post of terrence's at the same time i was reading about severloh. trouble is, what accounts for the remaining 2,100 casualties at omaha? i don't think that many were killed by mines. and the germans on the beach hardly had any heavy weapons. severloh's platoon had a 75mm but didn't (or couldn't) use it.

 

I concur with Jeff, no way he could have come close to killing 1500 out of a total of about 2400 actually KIA, Remember KIA is not the casualty number which includes wounded, missing and captured as well .

I am always suspicious of "might have" or "up to" but it "might" fall into poetic license .....Gordon will know.

If a MG 42 gunner had 3 barrels he would have to not let any one over heat and also let them cool but it is quite possible he had water to pour on the barrel. Still one would have to be such the barrels cooled somewhat slowly to keep from changing their annealing. .He sure as hell could not pee that much , LOL

Someone with a knowledge of metallurgy needs to address this in a proper was as it is beyond me. It is a great subject. I have already posted it but I did read that John Browning did a demonstration of his water cooled 1918/1919(?) .30 caliber and ran 20,000 rounds without a stoppage. I would like to see a reference on that one, is it true.?? ! Seems bad luck would get a few. That gun had a reservoir and hose to circulate the water.

I would love to know what the sustained cycle rate was on the MG 42 over, say, 10 minutes. Am not knocking that breakthrough design at all, greatly admire the mechanics, just curious ?

 

Thanks, Jeff for the map, good reference.

 

[salutes]

 

3 barrels may just allow for enough time between usage for them to cool down a bit, IIRC the MG42 doing continuous fire was good for 3 60 round belts before needing a barrel change, that's 240 barrel changes for 12.000 rounds and if he had 3 barrels he would use each around 80 times !,

For a simulation I'm working on I used the following for the MG 42

1200 RPM cyclic rate = 20 rounds per second
So 3 second to fire a 60 round belt
5 Seconds to change belt so it actually takes 8 seconds to fire 60 rounds
One barrel change (10 seconds) every 3 belts so 34 seconds for 180 rounds
That comes up to just above 300 RPM of real sustained fire

Anyone is welcome to punch holes in my calculation as it's quite likely I missed something.

Going back to the "beast of Omaha" it seems unlikely just 3 barrels would stand up to that sort of treatment with just over a minute between use, but assuming 300 RPM it takes 40 minutes to fire off 12.000 rounds, so we may allow for some barrel cooling time if the firefight lasted longer. As far as I know throwing cold water over a red hot barrel is just as likely to ruin the metal as to cool it effectively.

 

he was firing from 5AM to 3PM.

 

Artillery barrels do wear with firing. As the rifling wears and obturation decreases, the round will not travel as far. This is why artillery units keep a track of the number of rounds fired and in WW1 anf WW2 recalibrated guns after sustained periods of heavy firing. There were episodes at the end of the Somme campaign of 1916 when the worn guns resulted in poor artillery barrages and an unacceptably high proportion of short rounds.

I have not heard of the phenomena with small arms, .Some machine gun units with the water cooled vVckers-Maxim guns did fire tens of thousands of rounds in a day. A single MG company fired a million rounds in one barrage in 1916. Did this affect the beaten zone or was this something that could be solved simply by re-zeroing the weapon?

P.S What is the source for this ludicrous factoird about Serverloh about 1500 or 2,000 dead and 12,000 rounds? Over the 6-7th June total US V Corps casualties, not dead were c 2,500. Serveloh was in a good position overlooking one of four sectors of Omaha beach on which part of the 1st US Division landed. He was not involved in the massacre of the 29th Division whose first wave landing was depicted in the 1st half hour of Saving Private Ryan, 12,000 rounds would fill 48 ammunition boxes @ 250 rounds per box. Serverloh was the brew bitch for Lt Ferking's Op Party and there wasn't enough space for him in the OP bunker, which is why he was in the trench (still visible at WN 62) . Furthermore, killing 1,500 americans with only 12,000 rounds would have made him around 100 times more effective than any other soldier in WW2 or perhaps even history. in the WW2 Italian campaign the allies fired 80,000 more rounds of all calibres than Germans died in the campaign. Common sense alone should prevent someone from repeating the story in any military history forum.

Returning to the thread topic.

 

Firing thousands or rounds is likely to wear the barrel even in not especially "pushed to the limit" weapons like small arms, the effect is much more marked in large naval guns where barrel life is sometimes as low as 150 rounds with field artillery in between the two. A 10% hit rate with an MG is very hard to believe though a 12.000 rounds ammo expenditure is barely possible. Allied troops widely used "reconnaissance by fire" and the British still used WW1 style MG barrages for their water cooled guns and that will bring the kill ratio for ammo expended way down.

 

This is an interesting topic and I think Sheldrake and several others have thoroughly demolished the claims of this Severloh fellow.

I did want to comment on the general "wear and tear" of the barrels through sustained firing. We're talking about an MG42 here which is not particularly accurate to begin with. The whole idea was to lay out a "cone of fire" at 1200 rounds per minute (though you'd fire in bursts, not just hold the trigger down until the ammo can was empty). Still, a barrel wears by eroding the "throat" at the top (front) of the chamber and while that affects accuracy it's not a particular concern in a weapon like the MG42. You'd lose far more accuracy via the brass deposited in the barrel than by throat erosion - but again, that loss would only have an incremental effect on the effectiveness of the gun itself. It's not a sniper rifle, it's a machine gun.

The rapid cooling of the barrel, such as dropping it in water, would not adversely affect anything. I know that in precision rifle contests like the old Creedmor matches in England and similar matches in the US, rifles were commonly cooled by pouring water down the barrel. Of course these rifles didn't get nearly as hot as an MG barrel, but they were precision rifles (of a much lower grade of steel - ca 1880/1890) and suffered no ill effects. Repeated heating and cooling is not going to ruin the tensile strength of a high carbon steel barrel as found in the MG42.

 

First let me state that I consider the claims related to H. Severloh utter BS. That being said, some of the other information related is incorrect IMHO. I was a machine gunner in the Marine Corps for eight and a half years. For a period of time I also served as a machine gun instructor at Camp LeJeune (actually Camp Geiger). Jeff, you estimate of the max effective range is IMO way to low. I do not know the particulars of the MG 42 off the top of my head, but the M60 had a max effective range of 1,100 meters (slightly over 1200 yards) when deployed on a tripod with the T & E mechanism (traverse and elevation). So your 1000 yard "lines" are relevant. The M-60's successor, the M-240 Golf when deployed on a tripod and with the T & E mechanism has a max effective range of 1,800 meters. The MG 42 should be capable of similar ranges (someone with the appropriate book can look it up). At that range you'd be using area fire and utilizing the guns beaten zone to inflict casualties and suppress the enemy. It's hard to stand up, or even crawl with rounds splashing all around you. At 1,000 yards the gun would probably have a beaten zone 75 yards or so long and a couple yards wide, so simply traversing would enable the gunner to place rounds in a large area.

Tired Old Soldier wrote:

I'd tend to agree with you on the hit percentage, though the density of targets in the area, and the skill of the gunner could greatly increase the percentage. However, it is very easy to burn through 12,000 rounds. There were many times I took students to the range, where we drew 12,000 rounds per gun and expended them all during the course of the day. This included breaks and lunch, instruction periods and demonstrations, much of the time only one gun would be firing because you'd be working with that team, etc. so we weren't shooting much of the time whereas H. Severloh probably was.

There is a rather long thread on this subject elsewhere on this forum. Machine guns are specifically designed to be high rate of fire weapons and the barrel design and materials used make them more wear resistant to high round counts than a rifle or other small arms.

gtblackwell wrote:

You're talking seperate things. Cyclic rate is how many rounds the gun can fire if the trigger is kept depressed and assuming a constant supply of ammunition. For the MG 42 IIRC, it's around 1,200 rounds per minute (for comparison the M-60 has a cyclic rate of between 550-600 rpm , and the M-240G has three gas port setting allowing 650-750 rpm with position 1, 750-850 rpm with position 2, and 850-950 using position three). You also have a rapid fire rate of 200 rpm and a sustained rate of 100 rounds per minute. At the sustained rate the barrel doesn't heat as quickly and you can fire for an extended period of time before a barrel change, this also allows for a greater period of time for the spare barrel to cool. At 100 rounds per minute (sustained rate) you'll burn through close to 6,000 rounds in an hour long engagement. IIRC, the Germans were trained to change the MG 42 barrel every 250 rounds and the guns sustained rate was 300-350 rounds per minute. That does not mean that during the combat at Omaha that the gunner changed barrels by the book, I doubt they did.

KodiacBeer wrote:

While it is no precision bolt gun, that does not mean that the gun is inherently inaccurate either. The "cone of fire" effect is not the result of the gun being an inaccurate bullet hose, most of the round dispersion is a result of the rate of fire. If you were to map the round trajectories of a weapon with a lesser rate of fire, they would have a cone of fire also. Fire an M1 or an M16 slow fire, single shot, carefully aiming each round, all the trajectories will be fairly close and point of impact closely grouped, then fire on rapid fire. The mechanical forces of the operating system will result in the weapon producing a cone of different trajectories and a broadened area of impact. Per FM 3-22.68, under "Cone of Fire", "This pattern is caused primarily by vibration of the machine gun and variations in ammunition and atmospheric conditions."

 

USMCPrice, Thank you for the observations. They help a lot. I thought this had been previously covered but could not remember the thread. I used the wrong term, out of error. I was curiously about sustained fire over a period of time that would allow cooling, reloading, etc. You answer cleared that up nicely. I often read where someone says the MG 42 "shoots" 1200 rpm and think that misleading. I do understand cycle rate as a measuring system.

I would think the M60 and MG 42 rounds would be fairly close ballistically. The 7.62X64, is that correct ????( the 30-06) would seem to have a slight edge because of case length but modern powders may equal that out . In combat I doubt any difference would be noticed and the effective range should be similar.

 

you gents have a lot of lecturing to do. it seems media and the general populace are just too willing to believe that a lone german corporal single-handedly killed 1,500 americans in one day. one edition of the guiness book mentioned it. there're more than enough wiki and other online articles about severloh bolstering this claim (and a couple youtube videos.) in fact, it's only here in ww2f that's speaking against it.

thanks for the correction.