accuracy/efficiency of machine gun fire

[ArgusEye]

Ripped off from Intelligence Bulletin, Vol. II, No. 9, May 1944.

1. INTRODUCTION

The cyclic rate of fire of the German MG 42 is 25 rounds per second. Most of the disadvantages, as well as the advantages, of the gun can be attributed to this single characteristic. As a result of the high rate of fire, the gun has a marked tendency to "throw off," so that its fire stays on the target for a much briefer time than does that of the MG 34, which can fire only 15 rounds per second.

This section summarizes the German Army views as to the length of bursts to be used against hostile forces when the MG 42 is employed as a light machine gun or as a heavy machine gun.

2. AS A LIGHT MACHINE GUN

The Germans are instructed to fire bursts of from 5 to 7 rounds when they employ the MG 42 as a light machine gun, since an operator cannot hold his gun on the target for a longer period. The gun must be re-aimed after each burst. To enable the bursts to fall in as rapid a succession as possible, the Germans try to cut the aiming time to a minimum.

Under battle conditions the MG 42 can fire about 22 bursts per minute—that is, about 154 rounds. Under the same conditions, the MG 34 is capable only of about 15 bursts per minute, at a rate of 7 to 10 rounds per burst, totalling about 150 rounds. Thus the MG 42, used as a light machine gun, requires a slightly higher ammunition expenditure. Although the Germans believe that when the weapon is properly employed, the compactness and density of its fire pattern justify the higher expenditure, recent German Army orders have increasingly stressed the need of withholding machine-gun fire until the best possible effect is assured. Although the German defensive trick of "lying in wait" has been adopted partly to gain the tactical advantage of surprise, it also fits in with recent German efforts to conserve, not only ammunition, but all other matériel manufactured by the hard-pressed industries of the Reich and the occupied countries.

3. AS A HEAVY MACHINE GUN

German soldiers are instructed that when the MG 42 is employed as a heavy machine gun, sustained fire must be avoided at all costs. The German Army has ruled that the results of sustained fire are disappointing and that the expenditure of ammunition involved is "intolerable."

This, and the following German observations, do not apply, however, to fire placed on large targets at short range.

The Germans believe that if the compact beaten zone of the MG 42 is on the target, a burst of 50 rounds should be effective. If the burst is not on the target, the Germans are instructed to re-aim the gun and, if necessary, to adjust the sights.

The enemy considers it wrong to fire long bursts before fire for adjustment has been undertaken and observed. At a range of 2,000 yards, for example, the time of flight is 4.7 seconds. This means that the point of impact cannot satisfactorily be observed under 6 seconds. Six seconds of sustained fire results in an expenditure of 150 rounds. The German Army tells its soldiers that if they will wait to observe the point of impact in firing for adjustment, a burst of 50 rounds should then prove adequate.

While U.S. soldiers have expressed a healthy respect for the MG 42's high rate of fire, they agree that the gun's dispersion is very small—so small in fact, that they have frequently been able to make successful dashes out of the field of fire.

[YankeeDog]

So. That means between 8 and 9rounds fired every second, over the entire minute, for a mg42 hmg. Continuously. And that is the sustained fire rate but with breaks for barrel swaps?

Makes sense to me. And it's a far cry from the current state of affairs.

Generally, under most conditions an HMG42 crew would not want to sustain an effective ROF that high for any length of time. See Argus Eye's post above, which is an American Intelligence source, but more or less matches German sources I have read on doctrine and usage.

The most basic reason is ammo supply -- even assuming the crew spends 1/3 of their time swapping barrels (which is probably high), 8 rnds/sec (average) x 40 seconds/min firing = 320 rnds./min. Any leg MG team is going to run out of ammo in just a few minutes trying to sustain a ROF like that. A 250 rnd. box of belted 7.92mm weighs over 8kg. If the gun is throwing off more than 8 kilos of ammo/min., the local supply ain't going to last long.

So usually, they don't. German MG crews were trained to keep the sustained ROF more like half that, in the 100-200 rnd/min range. This was partially to improve accuracy but also to keep ammo usage to a reasonable level.

Maybe in specific situations an MG could sustain 300 rnds/min+ -- e.g., an MG in a bunker with stacks of ammo nearby. But not your typical leg infantry team. Occasionally blowing an entire 50-round belt on a single target in one 2-second trigger pull can be done when tactically important. But the gun crew has to be careful about how often they do this, or they run out.

[PzKfW]

I'll go with that, too. It's still a far cry from where we are currently. Also interesting is the "small area of dispersion" mentioned by the report above.

Looks like we don't have that either.

Generally, under most conditions an HMG42 crew would not want to sustain an effective ROF that high for any length of time. See Argus Eye's post above, which is an American Intelligence source, but more or less matches German sources I have read on doctrine and usage.

The most basic reason is ammo supply -- even assuming the crew spends 1/3 of their time swapping barrels (which is probably high), 8 rnds/sec (average) x 40 seconds/min firing = 320 rnds./min. Any leg MG team is going to run out of ammo in just a few minutes trying to sustain a ROF like that. A 250 rnd. box of belted 7.92mm weighs over 8kg. If the gun is throwing off more than 8 kilos of ammo/min., the local supply ain't going to last long.

So usually, they don't. German MG crews were trained to keep the sustained ROF more like half that, in the 100-200 rnd/min range. This was partially to improve accuracy but also to keep ammo usage to a reasonable level.

Maybe in specific situations an MG could sustain 300 rnds/min+ -- e.g., an MG in a bunker with stacks of ammo nearby. But not your typical leg infantry team. Occasionally blowing an entire 50-round belt on a single target in one 2-second trigger pull can be done when tactically important. But the gun crew has to be careful about how often they do this, or they run out.

[poesel]

I once heard the story that the Germans would saw off a few turns of the spring to reduce ROF. Is this true?

[JonS]

Also interesting is the "small area of dispersion" mentioned by the report above. Looks like we don't have that either.

I think you might be confusing Arthur with Martha.

[c3k]

Generally, under most conditions an HMG42 crew would not want to sustain an effective ROF that high for any length of time. See Argus Eye's post above, which is an American Intelligence source, but more or less matches German sources I have read on doctrine and usage.

The most basic reason is ammo supply -- even assuming the crew spends 1/3 of their time swapping barrels (which is probably high), 8 rnds/sec (average) x 40 seconds/min firing = 320 rnds./min. Any leg MG team is going to run out of ammo in just a few minutes trying to sustain a ROF like that. A 250 rnd. box of belted 7.92mm weighs over 8kg. If the gun is throwing off more than 8 kilos of ammo/min., the local supply ain't going to last long.

So usually, they don't. German MG crews were trained to keep the sustained ROF more like half that, in the 100-200 rnd/min range. This was partially to improve accuracy but also to keep ammo usage to a reasonable level.

Maybe in specific situations an MG could sustain 300 rnds/min+ -- e.g., an MG in a bunker with stacks of ammo nearby. But not your typical leg infantry team. Occasionally blowing an entire 50-round belt on a single target in one 2-second trigger pull can be done when tactically important. But the gun crew has to be careful about how often they do this, or they run out.

My bold. The WEIGHT of needed supply is critical. 8kg/min x 2 MG42/squad = 16kg/min/squad. 10 minutes of fire consumes 350 pounds of ammo. 9 men per squad... almost 40 pounds of ammo per man. It is simply not feasible.

[PzKfW]

LMGs within a squad, versus HMG positions. We need to understand what precise situation is being talked about here. They are VERY different situations, obviously. I can live with the squad LMG performance in game. The HMG is another story.

Are ammo limitations the problem with turning up the ROF "knob"? Isn't CM all about the realism?

I would much rather have the ROF "knob" turned up and be able to drain the gun dry if I didn't watch target arcs, etc... than to have the game "dumbed down" by limiting the ROF. At least turn up that ROF knob to max when the enemy are within 300-400m or so when using the "target" command.

I would want that 2.5k of ammo go to dry in 8 turns or so of full-on firing within that range. That is realistic. Harassing fire... that's "target light"...

Even for a HMG, I agree that ammo conservation is important. So are range considerations. A mg team's reaction and thus ROF to a group of guys at 700m is going to be a lot different than their reaction to a group of guys at 300m. The game does a poor job of really turning up the ROF in these situations.

I am not advocating full on HMG belt dumps in any case. I am advocating more rapid intervals of short bursts. Not 10-15 seconds between bursts... so ineffective for what was a really scary weapon. That goes for any HMG position. Such a low rate of fire for an HMG position is rediculous when the enemy are only a few hundred meters away, especially with the accuracy limitations and lack of suppression...

[poesel]

Has anyone ever run dry a HMG? I haven't. Usually the HMG dies long before because of HE. I haven't done the math but I doubt we can empty their ammo inside 30 minutes even with constant target orders without returning fire.

We can argue on the effects but this feels just wrong.

The argument that the troops would save on ammo does not work. Other troop types, tanks for instance, will happily deplete their ammo on area targets. It is my responsibility as commander to make sure that my pixeltruppen make the best use of their resources. BFC usually does no hand holding.

[FFE]

Hi Poesel71, I have HMGs that run out of MG ammo. It happens while on the defense. The last time it happened was two weeks ago during the Troina campaign when the Germans were counter attacking.

[JasonC]

On ammo loads in the field, that German standard was 1500 rounds per MG42 in LMG configuration, and 5000 rounds for an HMG team. Note that the latter figure is for a gun in position - the ammo team could not move that much in one go, but the gun could displace and the ammo team half of the HMG crew schlep the ammo pile to the new position in repeated runs.

Not everyone can carry boxed MG ammo, it takes a free hand or two. Independent of absolute weight, it is just awkward to try to run around a battlefield with 20 pound weights in each hand. The gunner has the MG itself to carry, the AG has a toolbag with heavy spare barrels and the like. Squad leaders or the team leader in the case on an HMG are not going to carry boxed ammo, they need their heads up and their wits about them. Normally only a single ammo bearer for the LMG would carry 2 boxes, for the HMG team that might be 2-3 guys doing that at a time. (The rest of the HMG team are leader spotting with binocs, gunner with the actual gun, AG with barrels and tools, a man to carry the tripod if moving, and making up linked belts or clearing away the debris of firing etc in position. Leaving only a couple of guys to run ammo up to the gun in boxes).

The ammo totals above are well above the boxed total from the men that can actually be spared for it. The difference is bandoliers spread across the whole MG team and sometimes other members of a squad. But the ability to physically man-pack ammo to the gun is always a serious limit on firepower for any MG - even the lowest ROF types could physically throw all available ammo is a very short period of time, compared to the length of combat engagements.

[Fernando]

On ammo loads in the field, that German standard was 1500 rounds per MG42 in LMG configuration, and 5000 rounds for an HMG team. Note that the latter figure is for a gun in position - the ammo team could not move that much in one go, but the gun could displace and the ammo team half of the HMG crew schlep the ammo pile to the new position in repeated runs.

Not everyone can carry boxed MG ammo, it takes a free hand or two. Independent of absolute weight, it is just awkward to try to run around a battlefield with 20 pound weights in each hand. The gunner has the MG itself to carry, the AG has a toolbag with heavy spare barrels and the like. Squad leaders or the team leader in the case on an HMG are not going to carry boxed ammo, they need their heads up and their wits about them. Normally only a single ammo bearer for the LMG would carry 2 boxes, for the HMG team that might be 2-3 guys doing that at a time. (The rest of the HMG team are leader spotting with binocs, gunner with the actual gun, AG with barrels and tools, a man to carry the tripod if moving, and making up linked belts or clearing away the debris of firing etc in position. Leaving only a couple of guys to run ammo up to the gun in boxes).

In an sMG team the MG gunner carried the MG while the AG carried the Lafette. It means there were three men available to carry ammo cans, spare barrels etc. Each ammo can could carry up to 300 rounds. Ammo can handles were designed to allow soldiers to wear a pair of cans on each hand. It means up to 12 300-round ammo cans could be moved at the same time by three men. That's 3,600 rounds. However if the MG was moved while the Lafette was deployed, three men were needed though a pair could do it too. I have tested it myself (I own a pair of Lafetten and MG's)

[JasonC]

Across a short space for 2 minutes, maybe. Nobody can maneuver on a battlefield carrying 40 pounds in each hand, on top of their personal weapon and equipment.

[LongLeftFlank]

Two man LMG team rapidly setting up a simple keyhole position or a base of suppressing fire to cover an assault, no problem. Find a spot to prop the bipod, preferably behind some solid cover, set up the belt feed or drum, and good to go!

MMG/HMG team displacing from their original (defensive) emplacement and expecting to set up shop again in another spot within the timeframe of a CM game, and while under heavy enemy fire? Not bloody likely, it seems to me. A fair amount of work would seem to be involved in selecting a location offering suitable fields of fire (without also being so visible that it becomes a magnet for every enemy weapon for miles around), clearing nearby obstructions, leveling it for the tripod, digging scrapes for the crewmen (who can't all hide behind the same rock), etc.

I suppose what I'm saying here is that I think an HMG unit that leaves its prepared position ought to be useless for the rest of the game, at least as an HMG unit. But I'm willing to be persuaded otherwise by historical data (not manuals). And I suppose a GPMG like the German MG34/42 might give you more flexibility than a "dedicated" HMG like a water-cooled Vickers.

[Killkess]

I suppose what I'm saying here is that I think an HMG unit that leaves its prepared position ought to be useless for the rest of the game, at least as an HMG unit. But I'm willing to be persuaded otherwise by historical data (not manuals). And I suppose a GPMG like the German MG34/42 might give you more flexibility than a "dedicated" HMG like a water-cooled Vickers.

Moving the MG and the Lafette should not be much of a problem. Taking a couple of thousand rounds with you seems to be the hard part. So it might be a good idea to cut the ammo level down if one moves this kind of unit.

In my mind the same should be true for mortar units. Whats the weight of ammo such a crew carries around? Cutting the ammo supply down, if they are moved, seems to be a good solution to the excessiv offensive mortar use.

[Fernando]

Across a short space for 2 minutes, maybe. Nobody can maneuver on a battlefield carrying 40 pounds in each hand, on top of their personal weapon and equipment.

I have done it several times in German uniform carrying full equipment in a reenactment unit. I own a MG34 and a MG42 Lafette and both MG's too.

The Lafette weights about 20 Kg, the MG42 weigths about 11.5 Kg. Thats 30.5 Kg (about 68 pounds), which I agree is a lot of weight.

The gunner holds both rear legs while the AG and a rifleman holds the front leg, one on each side of it. That's the way it was done at the time. It means each man carries about 22-23 pounds, not 40 as you said.

It is surprising how light it becomes and how easily it can be moved. However it is cumbersome and is not OK for extnded periods of time. Just for moving from one prepared MG position to a nearby one. However it can be done quickly provided the terrain allows it.

[Fernando]

Two man LMG team rapidly setting up a simple keyhole position or a base of suppressing fire to cover an assault, no problem. Find a spot to prop the bipod, preferably behind some solid cover, set up the belt feed or drum, and good to go!

MMG/HMG team displacing from their original (defensive) emplacement and expecting to set up shop again in another spot within the timeframe of a CM game, and while under heavy enemy fire? Not bloody likely, it seems to me. A fair amount of work would seem to be involved in selecting a location offering suitable fields of fire (without also being so visible that it becomes a magnet for every enemy weapon for miles around), clearing nearby obstructions, leveling it for the tripod, digging scrapes for the crewmen (who can't all hide behind the same rock), etc.

I suppose what I'm saying here is that I think an HMG unit that leaves its prepared position ought to be useless for the rest of the game, at least as an HMG unit. But I'm willing to be persuaded otherwise by historical data (not manuals). And I suppose a GPMG like the German MG34/42 might give you more flexibility than a "dedicated" HMG like a water-cooled Vickers.

I think it was standard practice to prepare several positions for each MG in defence, so it could be moved to a nearby postion if the one where it was deployed was targeted by heavy weapons. Obviously it means the MG field of fire, distances etc. were measured/checked for each position.

[JonS]

It means each man carries about 22-23 pounds, not 40 as you said.

He's talking about ammo, not the gun.

Moving weapons is trivially easy. Even artillery pieces can be moved reasonable distances at reasonable speeds.

But moving ammunition is a never-ending biatch. Always. For everything. Jason was responding to you suggestion that the spare men in HMG teams could each carry four of the uber opposing ammo cans, two in each hand. Which works out to around 40 pounds on the end of each arm. Which is not reasonable.

[Fernando]

He's talking about ammo, not the gun.

Moving weapons is trivially easy. Even artillery pieces can be moved reasonable distances at reasonable speeds.

But moving ammunition is a never-ending biatch. Always. For everything. Jason was responding to you suggestion that the spare men in HMG teams could each carry four of the uber opposing ammo cans, two in each hand. Which works out to around 40 pounds on the end of each arm. Which is not reasonable.

Germans were not silly people. There were other ways of wearing the ammo cans, not just at the end of both hands. Each of the three ammo carriers in a sMG team got a load carrying sling (Tragegurt 34) which was later replaced by the Munitionstrageeinrichtung für MG (carrying harness). The Tragegurt became obsolete in April 44. Both carrying items allowed a man to carry a pair of ammo cans while leaving both hands free.

The Tragestell 39 (carrying frame) was also used. If was similar in use to the US pack frame. It allowed you to carry several ammo cans and/or other kinds of equipment at your back leaving your hands free.

BTW, I guess you will notice that if you use the Tragegurt 34 or the Munitionstrageeinrichtung für MG, you can carry up to 6 300-round cans for a short period of time and distance. That's 5,400 rounds by three men.

I have several original ammo cans loaded with 250 deactivated rounds, which weight less than the full amount of ammo carried at the time. I fully agree ammo cans can be really heavy, specially if you hold a pair of them in one hand. However carrying a pair of cans on each side of your body helped by the Tragegurt or the Munitionstrageeinrichtung and a can in each hand, allows you to carry up to 1,200 rounds fairly easily for a short time. If you carry just a pair of cans helped by the Tragegurt then you can carry them for long distances and a lot of time while beign still able to use your rifle

[JonS]

Germans were not silly people.

...

BTW, I guess you will notice that if you use the Tragegurt 34) or the Munitionstrageeinrichtung für MG, you can carry up to 6 300-round cans for a short period of time and distance.

130+ pounds, PLUS standard weapon, webbing, and equipment? Yeah, that'd be a VERY short period of time and distance.

[Fernando]

130+ pounds, PLUS standard weapon, webbing, and equipment? Yeah, that'd be a VERY short period of time and distance.

From one MG prepared position to the next one which had been previously prepared for the same sMG.

I wanted to say that you can move a sMG team really quick from one position to a nearby one in a VERY short time.

Lastly, please, don't forget men didn't carry all the ammo themselves all the time. They were helped by the usually hose-drawn Machinengewehrwagen (If.5), the Infanterie Karren (If.8), the Hf.1 or whatever available. The norm was having one for each pair of sMG. You can carry LOTS of ammo cans there. Up to 30 or even more.

[LukeFF]

I have several original ammo cans loaded with 250 deactivated rounds, which weight less than the full amount of ammo carried at the time. I fully agree ammo cans can be really heavy, specially if you hold a pair of them in one hand. However carrying a pair of cans on each side of your body helped by the Tragegurt or the Munitionstrageeinrichtung and a can in each hand, allows you to carry up to 1,200 rounds fairly easily for a short time. If you carry just a pair of cans helped by the Tragegurt then you can carry them for long distances and a lot of time while beign still able to use your rifle

I think you're grossly underestimating how much effect the weight of all that ammo is when attempting to carry it. I've owned 900-round cases of live, military-surplus 7.92mm ammo, and they are very heavy. There is no way, like JonS said, you're going to get very far carrying 1800 rounds of ammo.

[Fernando]

I think you're grossly underestimating how much effect the weight of all that ammo is when attempting to carry it. I've owned 900-round cases of live, military-surplus 7.92mm ammo, and they are very heavy. There is no way, like JonS said, you're going to get very far carrying 1800 rounds of ammo.

If you carefully read me I say "moving an MG from a prepared position to another nearby one". It doesn''t mean 2 Km away but 30, 50 or 60 meters away. Any man in good phisical conditions can do it.

If you had to move for long distances almost all ammo cans could be carried in the Infanterie Karren. As a rule, TWO ammo cans were assigned to each of the three carriers. At the start of the war the MG leader also carried ONE ammo can. A Tragegurt 34 was also assigned to each of the carriers so they could carry the assigned pair of cans and beign still able to use their weapons, pass a spare barrel to the MG, join MG belts...or carry additional cans if needed.

If you was defending in a prepared positions, you could bring additional ammo cans from the Infanterie Karren/Machinengewehrwagen then move it out of harm. However if you had to move in a hurry to a near position (enemy was coming from another area, mortar or artillery fire was starting to hit near your actual position etc.), a carrier could carry up to 6 cans for a very short time.

OTOH don't forget that if you must move out of your actual position because you have been in action for a time it also means you have expend some ammo, so you don't be forced to carry the full load again, but just the remaining one. I.e. if your sMG team start with 5,000 rounds, expend 1,000 rounds, then you are ordered to move to a nearby position, your sMG team must carry the remaining 4,000 rounds, not the original 5,000.

Regarding weight it is not the same to carry a 900-round can in each hand than carrying two 300-round can in each hand and two cans on the body (helped by the Tragergurt) or carrying just one can on each hand and a Tragestell 39 loaded with 3 or 4 cans at the back. It sometimes heavily depends on how you distribute the weights.

BTW it was said in joke at the time that the arms of MG ammo carriers lengthened several centimeters during the war so they ended looking as Feldgrau orangutans

[PzKfW]

Just to head certain people off at the pass, sMG is the acronym for schweres Machinegeschutz (heavy machine gun). I agree with you Fernando. HMG positions are in any case more defensive in nature and thus ammo weight and mobility are less of a factor. On the whole, I feel the mobility of these teams is certainly over modeled in game, whilst their effectiveness is woefully under-modeled. Shooting minimal bursts as if it were a LMG, whilst retaining the same mobility of a LMG, makes it a bit more of a flavor unit than an actual heavy weapon position.

[sburke]

Stay tuned for the following conversation

US - Hey BF you need to lower the mobility of the sMG teams. They need to tire faster if going distances over say 60-80m.

BF- okay done sMG teams now tire faster

US- Hey wait a minute, my team was almost out of ammo they shouldn't tire so fast anymore. You need to add weight characteristics for EACH ROUND my guys are carrying and if they have the proper sling for carrying ammo cans.

BF- Go f**k yourself. (spoken very politely)

[stikkypixie]

Stay tuned for the following conversation

US - Hey BF you need to lower the mobility of the sMG teams. They need to tire faster if going distances over say 60-80m.

BF- okay done sMG teams now tire faster

US- Hey wait a minute, my team was almost out of ammo they shouldn't tire so fast anymore. You need to add weight characteristics for EACH ROUND my guys are carrying and if they have the proper sling for carrying ammo cans.

BF- Go f**k yourself. (spoken very politely)

I'm pretty sure ammo weight is already factored in actually.