One Machine Gun burst equals how many bullets?

[mg42 gunner]

Approximetley how many bullets come out of one burst form the machine guns ?

[Panzer Leader]

And your name is what?

I don't know about WW2, but nowadays they are 3-5 second bursts. I guess that would be what, 5-10 rounds?

[Slapdragon]

What MG, what is the situation, and who is firing it.

[JonS]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Panzer Leader:

... but nowadays they are 3-5 second bursts...<HR></BLOCKQUOTE>

Make that 3-5 rounds

[Tread Head]

I have a t-shirt I bought while serving a tour in Korea, it has a picture of a M60 on it. Under the 60 it says "Happiness is a 200 round belt and one solid trigger squeeze!"

A typical 50 cal. burst after you have walked your tracers onto the target is about 15-20 rounds. The manual may say less but that is what we did off of our tanks. Trust me that ammo goes quick. When there are crunchies around you have to conserve ammo, you have to expose yourself on a Abrams to reload your 50.

[JasonC]

The MG-42 fires 20 rounds per second with the trigger down. The other MGs fire about 8 bullets per second, typically using longer bursts, but not 2 1/2 times as long. An MG-42 burst might be 1-2 seconds, a burst from the others 2-3.

CM seems to use an ammo system of 25 rounds per MG shot, uncorrected for ROF, while the fp ratings are corrected for ROF. E.g. the M3 haltrack carried 4000 rounds for its 30 cal, and gets 160 CM shots. The weights of the loads each unit carries also seem consistent with this figure.

I for one have suggested modifying the ammo totals of the various MGs based on 25 rounds per CM shot for most - representing ~3 seconds of firing - and 40 bullets per CM shot from the HMG-42, representing ~2 seconds of firing. The fp ratios of the different guns are in line with that ratio of ammo expenditure. (E.g. HMG-42 fp at 250 yards is 1.6 times Vickers fp at the same range). Bipod LMG versions of the MG-42, with less ammo to burn and fewer spare barrels, are presumably firing somewhat shorter bursts again, judging by their firepower ratings. So I'd keep their ammo the same.

Note that in CM, an MG team may fire 4-8 times in a turn, depending on range, crew quality, suppression, target exposure, etc. The higher end of that range is less common, but the middle levels (6 shots a turn) are seen relatively often. That means a HMG-42 presumably has the trigger down 20% of the time in typical cases, while the others may have it down 30% of the time. Plus or minus about 5% in the first case, 10% in the second. An HMG-42 would commonly go through a 250-round full belt per minute at that rate of fire, while the same would last more like a minute and a half for the others.

The barrel life of the MG-42 was about 3500 rounds, sometimes a bit longer. Which means about 3 minutes of held trigger. That is not just for overheating - that comes even faster if the trigger is held continually - but for wearing out the barrel completely. So you can see how impractical it would be to hold the trigger down forever. Not to mention running out of ammo, since the barrel life figure is above the load the team could easily move on their own.

[jwxspoon]

I agree...if you've ever tried to change the barrel on an M60 while that sucker is red hot you haven't had any fun. I've also seen an M16 barrel get so hot that it turned the barrel white, the flash hider unscrewed itself and the handguards melted up front.

[MoatnGator]

Typically you rotate barrels for that not to happen. That is why there is more than one person on th team and their rate of fire goes down as the team members are killed.

We had asbestos gloves to grab those smoking barrels as not to burn our little fingers off. Boy is smarts when you forget the gloves. It has been awhile, but I believe a ruff figure for a barrel change on a M60 is about 15-20 seconds.

Any fool who held the trigger down, would quickly find themselves out of ammo. In the game you see bursts, which is correct.

[Mark IV]

Any fool who held the trigger down found a Drill Sergeant's boot in a painful place.

They were even more strict about the .50 on the commander's cupola (on M60A1); use slow rate and short bursts wherever possible.

The .50 was the quickest solution to ATGMs and attack helicopter threats, while the rest of the tank got into gear. It had to be ready to rock at all times.

Infantry has long known that sustained full auto anything draws major fire and destroys equipment at the most inconvenient times.

[Andreas]

<BLOCKQUOTE>quote:</font><HR>Originally posted by JasonC:

The MG-42 fires 20 rounds per second with the trigger down. The other MGs fire about 8 bullets per second, typically using longer bursts, but not 2 1/2 times as long. An MG-42 burst might be 1-2 seconds, a burst from the others 2-3. <HR></BLOCKQUOTE>

Are we talking lMG or HMG? The lMG should be a 3-5 round burst, at least that is what they taught us on the MG3.

Regarding happyness being a 200-round squeeze - in WW2 this would have led to your MG being unusable in a very short time, and to ammo cook-off (not necessarily in that order). Not sure if metallurgy advanced a lot post-war, but from what I have read the likely consequence of this in a Sherman was that the rounds would just drop a few yards from the barrel. Tankers still did it (not having to carry the ammo seems to encourage that ) though.

[Andrew H.]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Germanboy:

Not sure if metallurgy advanced a lot post-war, but from what I have read the likely consequence of this in a Sherman was that the rounds would just drop a few yards from the barrel. <HR></BLOCKQUOTE>

IIRC, the only significant advance in gun-barrel metallurgy is a harder lining (I've forgotten the name of the alloy) for the inside of the barrel that prevents the barrel from wearing as quickly as WWII barrels did. I don't think that it had any effect on the barrel's resistance to heat.

[Andreas]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Andrew Hedges:

IIRC, the only significant advance in gun-barrel metallurgy is a harder lining (I've forgotten the name of the alloy) for the inside of the barrel that prevents the barrel from wearing as quickly as WWII barrels did. I don't think that it had any effect on the barrel's resistance to heat.<HR></BLOCKQUOTE>

Ah yes, rings a bell - the lining was the problem, at least with the South Albertas.

[Slapdragon]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Germanboy:

Ah yes, rings a bell - the lining was the problem, at least with the South Albertas.<HR></BLOCKQUOTE>

It would not since mass is directly related to the ability of an object to soak up heat, while conductivity says how past that heat will be soaked up. Pretty much you have three tactics for cooling: run a high conductivity fluid over the barrel and into a radiator (or replace the fluid as it boils off), maximize surface area, or maximize mass. Lead would make a great heat sink, so does iron. Aluminum makes a poor heat sink, and so do light alloys. Low conductivity heat sinks like silicon will be counterproductive since they keep the heat in the metal longer.

[Andreas]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Slapdragon:

It would not since mass is directly related to the ability of an object to soak up heat, while conductivity says how past that heat will be soaked up. Pretty much you have three tactics for cooling: run a high conductivity fluid over the barrel and into a radiator (or replace the fluid as it boils off), maximize surface area, or maximize mass. Lead would make a great heat sink, so does iron. Aluminum makes a poor heat sink, and so do light alloys. Low conductivity heat sinks like silicon will be counterproductive since they keep the heat in the metal longer.<HR></BLOCKQUOTE>

Sorry, I meant the lining went, not due to heat, at least as far as I understand it. Or maybe due to a combination. I am no gun expert, the less I have to do with these blasted things, the better.

[Slapdragon]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Germanboy:

Sorry, I meant the lining went, not due to heat, at least as far as I understand it. Or maybe due to a combination. I am no gun expert, the less I have to do with these blasted things, the better.<HR></BLOCKQUOTE>

A barrel degrades both by heat and by passage of bullets along the rifled interior. Each bullet minutely wears the barrel down a small amount, but that wear is increased the hotter the barrel gets and the higher the recoil stress placed on the barrel. Hot enough, and the bullets can mold out the rifling in a few rounds of firing, and eventually effect the gas seal of the chamber.

Other weapons wear as well, but not as much. Pistols only rarely need to have a new barrel even after tens of thousands of rounds: the ammo is much slower, loaded at lower pressures, and the barrel rarely gets extremely hot. Most pistol barrels get replaced because they get cleaned wrong.

Andreas, when you come to the US I will take you shooting on the police range with as many different weapons as I can lay my hands on just to give you a taste. You never know, you may go back to the UK and apply for your permit.

[russellmz]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Mark IV:

Infantry has long known that sustained full auto anything draws major fire and destroys equipment...<HR></BLOCKQUOTE>

not to mention infantry...

[Hon John Howard MP LLB]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Slapdragon:

A barrel degrades both by heat and by passage of bullets along the rifled interior. Each bullet minutely wears the barrel down a small amount, but that wear is increased the hotter the barrel gets and the higher the recoil stress placed on the barrel. Hot enough, and the bullets can mold out the rifling in a few rounds of firing, and eventually effect the gas seal of the chamber..<HR></BLOCKQUOTE>

Actually it is a function of friction of the bullet passing down the rifling, heat, velocity of expanding gasses (at muzzle), corrosion due to chemical properties of the gasses, pressure on the barrel (all of the above). Recoil has no effect except on accuracy (and the shoulder of the firer !).

[Slapdragon]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Hon John Howard MP LLB:

Actually it is a function of friction of the bullet passing down the rifling, heat, velocity of expanding gasses (at muzzle), corrosion due to chemical properties of the gasses, pressure on the barrel (all of the above). Recoil has no effect except on accuracy (and the shoulder of the firer !).<HR></BLOCKQUOTE>

Not true about recoil stress. Recoil stress is the stress placed on the barrel bu the rearward and sideward (spin) forces of the barrel. As a barrel heats up, these stress warp a barrel, cause metal to crack, and a barrel to quickly become useless. Corrosion is not a factor in a wartime barrel that is in combat because the barrel will "shoot out" because of recoil force and friction before even the most poorly treated barrel's bore will rust out. Gas pressure and expanding gasses effect the fit of the bolt and can damage the bolt, but rarely if ever damage an intact barrell.

On a cold barrel, such as one of a hunting rifle, this is true, but a barrel being fired in combat that heats up suffers a great deal from recoil. This is also true of cannons that fire rapidly.

[ 08-30-2001: Message edited by: Slapdragon ]

[Tread Head]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Germanboy:

Regarding happyness being a 200-round squeeze - in WW2 this would have led to your MG being unusable in a very short time, and to ammo cook-off (not necessarily in that order).

Tankers still did it (not having to carry the ammo seems to encourage that ) though.<HR></BLOCKQUOTE>

I tell you what, a 50 cal can run through a 100 rd belt with ease. If the head space and timing are set right. You are right about wasting ammo though. Being on a tank had pro's, we carried plenty of Ammo!

Happyness is a 100 rd. belt and one solid trigge squeeeeeeese!

[Slapdragon]

Gunners on the ground could still run through a lot of ammo. Using more ammo for less effect is a sign of green troops.

[Brian]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Andrew Hedges:

IIRC, the only significant advance in gun-barrel metallurgy is a harder lining (I've forgotten the name of the alloy) for the inside of the barrel that prevents the barrel from wearing as quickly as WWII barrels did. I don't think that it had any effect on the barrel's resistance to heat.<HR></BLOCKQUOTE>

Its called "stellite" and was first used in airborne .50 cals on USAAF bombers (notably B-17 & B-24). I have no idea if it was applied to other weapons in WWII but was/is commonly used in small arms today.

[Tread Head]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Slapdragon:

Gunners on the ground could still run through a lot of ammo. Using more ammo for less effect is a sign of green troops.<HR></BLOCKQUOTE>

Sure Green troops and trigger happy tankers!

[Michael Dorosh]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Germanboy:

Ah yes, rings a bell - the lining was the problem, at least with the South Albertas (emphasis Mike's)<HR></BLOCKQUOTE>

You must really have liked that book eh?

To further a point made elsewhere, this is what the professional historian likes to see - any historian worth his salt usually feels the necessity to qualify his remarks - "in the opinion of", "in my personal experience", "in the case of" etc. Provides much more ground for intelligent discussion (and also, not coincidentally, a way to back out of something you've said if someone calls you on it!)

Are there any British regimental histories that you are aware of that are in the same league as "South Albertas at War"? Either armoured or infantry? The more I read about the British the more interested I find myself becoming.

[ 08-31-2001: Message edited by: Michael Dorosh ]

[Andreas]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Michael Dorosh:

You must really have liked that book eh?

To further a point made elsewhere, this is what the professional historian likes to see - any historian worth his salt usually feels the necessity to qualify his remarks - "in the opinion of", "in my personal experience", "in the case of" etc. Provides much more ground for intelligent discussion (and also, not coincidentally, a way to back out of something you've said if someone calls you on it!)

Are there any British regimental histories that you are aware of that are in the same league as "South Albertas at War"? Either armoured or infantry? The more I read about the British the more interested I find myself becoming.

[ 08-31-2001: Message edited by: Michael Dorosh ]<HR></BLOCKQUOTE>

I do really like that book - by far the most informative regimental history I have seen. Unfortunately I have yet to see one in similar quality for a British unit. Delaforce does not come close - 'Tank tracks' is good, but taking 'The SAR' as a measure of 100, it would be around 65 (most of Delaforce comes in at 25-50). The DCLI regimental history is interesting, but not objective (50). A nice one is the 'Illustrated History of 6th Airborne (70-80). YMMV. I am still looking - future purchases include 'Only the Enemy in Front', the history of the Recce Corps, and 'Battleaxe', the history of the 78th Division. I'll let you know then.

[Username]

The burst length can also be a function of enemy proximity and magazine limitations (in infantry weapons). hence the value of a belted option, if need be barrel be damned, and go for broke.

Another factor is time between bursts (whatever the length of the burst) or what the duty cycle is.

The greater the range, the longer the down time in the duty cycle. You have to observe the impacts to guage effects and adjust accordingly.

Firing blanks gets weapons red hot also. i wonder what the source of real heat is, friction or the temp/pressure? Is rifling a factor?

Lewis