Heavy machine guns and suppressive fire

[Sgt Joch]

zonks40, thanks for the comments. It is always greatly appreciated when we can get feedback from people with actual experience, especially since the MAG58 has a similar design and shares certain design elements with the MG42.

I was wondering if you could clarify two points in your post. When in combat, do you stick with the 5-8 rounds bursts or fire longer bursts? and what would be a typical burst when using the tripod?

[Redwolf]

I did two test runs, using a HMG42 in a crater and a platoon of US infantry using "quick" across 1000 meters of open ground. I'll make the test "scenario" available after fixing one issue.

In one test the HMG was overrun, in the other it stopped the last non-broken men about 50 meters out. But that doesn't mean the second run was OK because I did not even bother spreading the platoon out, getting them into any formation or even keep the HQ back. The run that was stopped ran out of steam when the HQ, which was in front, was killed. Having 30 men in the same beaten zone all running (not shooting) at the same time was not something that the combat mechanics decided would be suicidal.

Having said that, we aren't back in CMBO land either.

I will set this up with at least giving a wedge formation and a bit of spread out to the attacker, then run it again and make it available for download.

[Fūrinkazan]

I did a quick test on a 700 m map

4 HMG in bunker against one company without heavy weapons 121 men if i remember well. all troops are regular level

In hot seat :

no order for MG and the attacking infantry moving fast :

29 dead and 27 wounded

with fire arcs : 18 dead and 10 w

all this in about 5 minutes

each time the infantry could reach and attack with grenades the bunker, not all the squads of course but one or two and all were at about less than 200 m of the bunker lines.

In real time with Ai

with targeting order for hmg : 23 dead and 23 w 1 bunker destroyed

without order : 21 dead and 14 w

about 5 minutes battle each time.

the difference is that the ai stops at about 200 m and open fire to suppress the bunkers.

the hmg had a pause between each burst of about 5 sec.

For the german squads, the lmg gunner are expected to shoot 5 to 8 burst in 30 sec : this means 6 to a 4 seconds between each burst with about 50 to 60 rounds fired.

I think in the game it's correct for mg in squads (bipods) but maybe not for HMG.

It doesn't seem that emergency situations, infantry trying to assault bunker, change the pause time between each burst.

I doubt that in real life infantry would have reach the mg positions in open ground without cover after 600 m of running and under the fire of 4 HMG with a lot of ammo.

As i said, i have seen WW 2 movies, from the battle of Stalingrad, and they were firing without pause a lot of ammo, it was to pin down snipers in that case.

I think reducing the pause time between each burst, when infantry is close enough to be a danger, and maybe increasing the suppression effect should help.

It could be interresting to test with 0.50 hmg. I think the suppresion will be much higher and that the infantry would be pinned down. I noticed this in CMSF if i remember well.

[Peregrine]

Have any of you guys played the second Courage and Fortitude scenario? This shows how difficult it can be in an actual tactical scenario.

[LemoN]

Have any of you guys played the second Courage and Fortitude scenario? This shows how difficult it can be in an actual tactical scenario.

If the arty wouldn't be there it would be a cakewalk.

[Zonks54]

zonks40, thanks for the comments. It is always greatly appreciated when we can get feedback from people with actual experience, especially since the MAG58 has a similar design and shares certain design elements with the MG42.

I was wondering if you could clarify two points in your post. When in combat, do you stick with the 5-8 rounds bursts or fire longer bursts? and what would be a typical burst when using the tripod?

At the range we would use the regulation 5-8 round bursts with a bipod, (unless it was at the end of the financial year and had to use up our ammo allocation or get given less in the next year)

The reason behind the 5-8 round bursts is that when you fire the machinegun at a specific tartget you aim at the legs and it walks up the target as it kicks back.

In the field it basically comes down to the situation, If I had a squad coming at me in open ground, I could easily increase the rate of fire to 20 round bursts, even full rock & roll as the saying went, the adrenaline alone would ensure a much firmer grip on the weapon, where at the range it's much more relaxed.

When the machinegun is used on a tripod it is usually being used as a support weapon, we would setup 4 MAG58s on tripods from our Battalion support company, these machineguns would then fire upon an enemy position from up to 1000m away as a prelude to an assault on the enemy, we called it harrassing fire, basically hosing down an enemy position to keep their heads down, the rate of fire from the tripod could be anything up to 100 round bursts or more, but mostly around 50 rounds, the control of the weapon from a tripod is nearlly total, and a 50 round burst is only 3 seconds.

[Magpie_Oz]

Aussie doctrine for M60 was 5 to 10 on the bipod and 10 to 20 on the tripod. Change the barrel every 200 rounds. Sustained bursts for initiating an ambush or the peak of the cover fire as Zonks said.

Note too you didn't really aim at specific targets as such more usually an area.

[Wengart]

So I just ran a quick test German Fusiliers Platoon advancing at quick against a U.S. M1917 HMG and the 4 man ammo team in a trench. The MG caused 1 casualty at roughly 600 meters, another at 500, and finally killed 2 fusiliers who had entered the trench it was stationed in.

Meanwhile the accompanying riflemen knocked down 2 targets at 410 meters and then continued to rack up a further 7 kills until their position was overrun.

Thats 9 rifle kills to 4 HMG kills, although only 2 of those kills were outside of 10 meters.

[Wengart]

Ran a test map, five 200 or so meter wide sections 1000 meters long 1 HMG42 vs. 1 American Rifle Platoon Late.

Okay so I couldn't get the HTML to show up here, so I posted my spreadsheet here

KEY

DNE: did not engage

-->: The HMG team begins to fire small arms

TOTAL: total number of enemy killed

RESULT: what happened to the HMG team

Method: I played hotseat and started an American platoon 1000 meters from an HMG42 in a one story house. I then gave the American Platoon a quick order to enter the house. Whenever a squad stopped I would reissue the quick order.

The terrain was flat and made of grass.

I counted all casualties until the HMG was either knocked out or obviously not firing. (had I not the first regular team would have 5 more kills thanks to a prolonged burst from the team leaders MP40)

[Broken]

So I just ran a quick test German Fusiliers Platoon advancing at quick against a U.S. M1917 HMG and the 4 man ammo team in a trench. The MG caused 1 casualty at roughly 600 meters, another at 500, and finally killed 2 fusiliers who had entered the trench it was stationed in.

Meanwhile the accompanying riflemen knocked down 2 targets at 410 meters and then continued to rack up a further 7 kills until their position was overrun.

Thats 9 rifle kills to 4 HMG kills, although only 2 of those kills were outside of 10 meters.

Yes, we are almost back to CMBO HMGs, meaning not worth the purchase cost. Unless their effectiveness is boosted by whatever means, HMGs and MMGs will be stripped from most people's Quick Battle purchases. This is unfortunate, since MGs add a lot of richness to infantry tactics.

Battlefront might be a little leery of making MGs too effective. There were a lot of complaints in this forum during the transition from CMBO to CMBB about how tough it was on the attack with all those nasty MGs out there.

[Redwolf]

Ran a test map, five 200 or so meter wide sections 1000 meters long 1 HMG42 vs. 1 American Rifle Platoon Late.

Okay so I couldn't get the HTML to show up here, so I posted my spreadsheet here

KEY

DNE: did not engage

-->: The HMG team begins to fire small arms

TOTAL: total number of enemy killed

RESULT: what happened to the HMG team

Method: I played hotseat and started an American platoon 1000 meters from an HMG42 in a one story house. I then gave the American Platoon a quick order to enter the house. Whenever a squad stopped I would reissue the quick order.

The terrain was flat and made of grass.

I counted all casualties until the HMG was either knocked out or obviously not firing. (had I not the first regular team would have 5 more kills thanks to a prolonged burst from the team leaders MP40)

I have noticed (but just with sample size 1) that you have to give the HMG a covered arc to make it fire at the platoon running at it. Without the covered arc it would do almost nothing.

[Lanzfeld]

I have noticed (but just with sample size 1) that you have to give the HMG a covered arc to make it fire at the platoon running at it. Without the covered arc it would do almost nothing.

Thank you for pointing this out!

I have been wanting to test this forever but it just got lost in the mix. So covered arcs make the MG teams more prone to shooting I guess? I sort of sensed this but I never ran a proper test.

I REALLY WISH THIS WAS IN THE MANUAL.

All MG teams get that ugly covered arc.

[Redwolf]

Here is a very simple test case.

A trench with a German HMG 42 and a forward observer (so that there is C&C). An American rifle platoon does a "quick" move towards the trench, nothing else. Over 950 meters of open ground.

Savegame: it is hotseat, no password. Just press the red button until the battle is resolved.

http://redwolf.dyndns.org/cmbn/hmgtest1/test-hmg-savegame.bts

[YankeeDog]

Thank you for pointing this out!

I have been wanting to test this forever but it just got lost in the mix. So covered arcs make the MG teams more prone to shooting I guess? I sort of sensed this but I never ran a proper test.

I REALLY WISH THIS WAS IN THE MANUAL.

All MG teams get that ugly covered arc.

Yes; just as in CMx1, a Cover Arc makes any unit (including MG teams) more likely to shoot at any enemy units that they spot within the arc. So by setting a long-range Cover Arc, you can increase the chance that a unit will fire on an enemy at distances where the "default" TacAI might decide it's better to withhold fire and conserve ammo.

BFC has also commented that Cover Arcs cause units focus their spotting efforts towards the arc area, and so relatively narrow Cover Arcs can increase spotting chances within this arc (at the cost, presumably, of spotting outside of the arc).

[c3k]

Wengart,

Thanks for running several iterations and posting results. Ditto to Furinkazan and Redwolf.

[Blackcat]

A lot of interesting posts since I had to go off to do chores around the house and its is good to se that see other have set up their own tests. If you’ll forgive what may turn out to be quite a long post I‘d like to comment on some of the points raised.

Distance at which AI opens fire

When running my tests I was interested in how the game behaves so I issued as few orders as I could get away with, intervening only to to keep the infantry moving when necessary and, in the walking tests, to stop the infantry breaking into a run. I gave no orders to the HMGs.

Therefore, whilst I accept Yankee Dog’s point that the player can intervene to force the MGs to open fire earlier, left to its own devices the game does seem to wait too long. Sgt Joch made the point that the AI should open fire as soon as the infantry is seen, which in my tests was a soon as they started moving i.e. at about 1000 metres (I played hot-seat so I was able to establish exactly what was going on). I think I would add a condition to the suggestion and say that the AI should open up as soon as the infantry is seen and there a reasonable chance of the fire having an effect. I actually think the AI may well be doing just this.

In my tests veteran HMG crews started firing when the enemy were at a shade under 900 metres whereas regular and green crews held fire until the infantry were at about 600 metres, even though they had them spotted at 1000 metres. I suggest that there is good evidence to indicate that the AI will open up as soon as it thinks it will do some damage. The question in my mind is whether the modelling of MGs is such that effective fire should be possible at longer ranges.

Given everything I have read about MGs in WWI and WWII, the personal experiences of posters here and my own time as GPMG gunner (granted that the last two were not with WWII weapons, but the capabilities and ballistics haven’t changed that much) is that tripod mounted MGs were, and so should be in the game, effective against infantry targets out to at least 1000 metres - particularly if they are moving in the open.

The question I then ask is why aren’t they, and that brings me on to bullet drop.

Bullet Drop

Sgt Joch has unearthed some interesting facts about the performance of the 7.92 ammo. It would seem that in WWII the most likely cartridge that would be used by an MG42 is the 197 grain Schweres Spitzgeschoss or “heavy pointed bullet” and there is a table giving the performance of a very similar modern equivalent (the F.N. 197.5 grain 7.9).

According to that table we can see that to hit a target at a 1000 metres the bullet will reach a maximum height of some 14 feet before hitting the target area at an angle of just over 1 degree above the horizontal. So, whilst there would be a safety zone at about the 500 yard mark, at the receiving end thee would be a beaten zone of a very elongated ellipse and the effect of such a shallow angle would not be much different to grazing fire. You can do the maths if you want to, but I would guess anybody standing from 900 to 1100 metres would be liable to be hit. So we are not in the esoteric world of plunging fie at this distance. Furthermore, the MG4 was sighted to 2000 metres,so I would expect a regular, let alone veteran, crew to be able to put down effective fire at 1000 metres. Maybe range estimation at that distance might be a stretch for a green team, but given, tracer rounds and the lack of incoming fire even that might be moot.

Accuracy

Once again I am indebted to Sgt Joch for the work he has done on the basic accuracy of the MG42 as modelled in the game. He states he is satisfied that the weapon is sufficiently accurate. I wonder if in fact it is too accurate.

Zonks40, makes the point that when using a MG in bi-pod mode, he was trained to fire in 5-8 round bursts because anything longer would end to make the fire too inaccurate to be effective. However, MGs are designed so that the bullets spread laterally. That is their purpose. They are not supposed to hit a point target but to put down bullets on an area (one of the criticisms of the Bren was that a burst produced too tight a group and so made it less effective than it needed to be). The point was also made that when mounted on a tripod longer bursts could and would be used, the basic accuracy was not affected but the longer burst gave a greater supression effect on the target.

Over the years of playing CM games I have wondered if BF’s fundamental modelling of MGs has been based on hitting a target; treating them as a fast firing rifle in effect rather than as an area weapon. It would explain a lot, including the CMBB “fix” mentioned by one poster. In support of this theory I will mention one incident I saw when I was running some tests yesterday.

You will be aware that when a section is given a “Move” command they tend to walk in more or less a single file. In one run though the centre squad was walking pretty much straight towards the HMG there were five men in a straight line with the others a yard or two on either flank. A burst from the HMG hit the section and the five in a line were mown down but the others were not touched. This was at a range of about 500 metres. So a bullet spread of less than one metre at 500 metres from a MG, again you can do the maths if you want but I suggest that is too tight a group.

Traversing Fire (aka the 2 inch tap)

Aide from the bullet spread built into the gun there is the issue of traversing fire. I don’t kno how this was done in other armies but in the British it was achieved by means of the “two inch tap”. Put simply the gunner of a Vickers HMG would use a slightly loose clamp on the tripod and after firing a two or three second burst he would tap the breach of the gun to move the barrel over an inch or two, just sufficiently far to put down another beaten zone which slightly overlapped the first before firing another burst and so on. In anything other than a hasty action stakes would be put into the ground to limit the traverse. Traversing fire is simply absent from the game, yet it was an essential part of the use of HMGs, especially in defence.

This issue could be addressed if BF take up the suggestion to allow “Linear Area Fire" as suggested on other threads. It should also be noted that the Tap regulates the time between bursts which has also been mentioned. In the sustained fire role using a water cooled MG the rhythm of the tap suggests a gap of only one or two seconds between long, in CM terms, bursts

Casualties and Suppression

I am with Redwolf on this one, I don’t expect to see mass slaughter from one HMG and the morale effects are important. However, a platoon of infantry, reasonably spaced out, walking towards an HMG for a full kilometre across open ground should not arrive within effective rifle range with very few casualties, so few that their firepower is barely affected. The same goes for quick movement i.e. running.

I think JasonC said we should discount the Somme, I don’t think his reasons for his view stand up, but look at it the other way. If someone can show me an example when a group of men walked towards a hostile MG for 800 metres across open, terrain in full view of the gun the whole time and didn’t take serious casualties then I’ll be prepared to consider that the modelling of HMGs in CMBN is not underpowered when it comes to causing casualties.

A suggestion has been made that the effects of suppression should be made to last longer an that would do much to address any under-modelling of HMGs effectiveness. There my be a case to be made that suppressive effects should last longer in general, though I haven’t seen any evidence to suggest such a thing would be good idea. However, the problem with HMGs is that they don’t produce enough suppression in the first place, e.g. a run of 800 metres through a single MGs field of fire and the worst effect is “Cautious”.

Concluding Thoughts

I believe that there is now sufficient evidence to suggest that HMGs may well be underpowered in the game. The problem was probably there in CMBF but the nature of that game was that there was very little reason to use HMGs at any longer range than a few hundred yards - as a Syrian it to open up at long range was to invite instant death and close in ambushes were more suited and as the allies one had enough firepower for it not to matter.

From a user perspective I am not sure how much further we can go. We could run some more tests and produce lots of tables of results. I am not sure that it would reveal too much more than we know already and it would be very time consuming. I would be prepared to put the work in, but only if there was a commitment by BF to look at the issue.

I am very hesitant to suggest solutions at this stage but some ideas that might be worth exploring are:

allow the TACAI to open fire at longer ranges

give MGs a greater bullet spread

introduce linear fire to simulate traversing

I have no idea how difficult it would be to implement any of those and of course it maybe that BF will decide that the game works well enough as it is.

Absent any comment from BF I think all we can do is make the best of it and remember if you are tempted to rely on a single MG to guard a flank - it won’t. Use them in pairs.

P.S. To those who have asked fro a copy of my test map and scenario they will be in the mail this evening.

[Reaver]

Wow, excellent post Blackcat! Some impressive detail.

Would linear area fire be difficult to implement? It strikes me as being similar to what on map mortars are doing currently when given a linear IDF order by a Forward Observer. If I am seeing things correctly, the green targetting line from the mortar shifts along the thick band of the linear target area every few rounds in order to achieve the linear fire order. Is this the case? If so, would it be hard to transfer to non indirect fire units?

[Sgt Joch]

Blackcat,

nice summary. The issue has been raised in the Beta forum and were are waiting for feedback.

btw, this thread is a good example of how to present an issue and get a response from Bfc. Multiple tests showing how the game actually works makes it a lot easier to see if there is a problem and what the solution could be.

As an additional comment on the subject, it appears using target arcs and, presumably, TRPs would increase the HMGs effectiveness. I wonder if someone could test this. TRPs should represent the MGs having previously pre-registered the range.

Second, area fire is supposed to be spread on the action spot and the adjacent spots. Perhaps someone could test troops attacking through such "area fire" to see what the result is.

[Wengart]

Thanks for the post Blackcat.

I ran two more test runs which are now also posted here

As an additional comment on the subject, it appears using target arcs and, presumably, TRPs would increase the HMGs effectiveness. I wonder if someone could test this. TRPs should represent the MGs having previously pre-registered the range.

I'll run a test or two with TRPs however in my one test with a target arc the MGs opened fire earlier, however they were not more effective.

[Wengart]

Just finished, TRPs help out regular crews quite a bit while veteran and elite crews do not benefit much, or at all from them.

Using target area on places the American platoon is running through results in more kills for a regular crew, however they lack the kill rate jump when small arms joins in and the 0-99 meter range netted them no kills.

Once again all HMG teams were destroyed. It seems that if the HMG is unable to break them the platoon will overrun their position while if the HMG is able to break them the broken squads will set up a base of fire which proves devastating to the HMG team.

[Broken]

What Blackcat said.

[Sgt Joch]

Reviewing the historical record, I am wondering if we expect too much from a lone unsupported HMG. The Germans normally used their HMGs as part of an integrated defence where they were supported by covering fire from other HMG/LMGs and mortars.

From Doubler, "Busting the Bocage":

In addition, the Germans organized each field as a defensive strongpoint and confronted the attacking Americans with a deadly mixture of direct and indirect fires (see figure 2). The Germans employed their direct-fire weapons to trap American infantrymen in a deadly hail of cross fire and grazing fires coming from all sides. Machine guns were the primary weapons of the German defense. At the opposite corners of each field, the Germans emplaced heavy machine guns in positions dug into the earthen embankments of the hedgerows. The purpose of the heavy machine guns was to pin down attacking infantrymen in the open, making them easy targets for small arms and preplanned indirect fires. Light machine guns and machine pistols supplemented the fire of the heavy machine guns and were emplaced in other firing positions to the front and flanks of the attackers. The Germans also used their light machine guns to place bands of grazing fire along the bases of hedgerows paralleling the American attack. The purpose of the grazing fire was to inflict casualties on American infantrymen seeking cover and concealment during their advance. Indirect fire was a key component of the German defense. Once pinned down in the open, preplanned artillery and mortar fire punished American units. German mortar fire was particularly effective, causing as much as 75 percent of all U.S. casualties during the Normandy campaign.5

The Germans also implemented other measures to improve their scheme of hedgerow defenses. They habitually dug slit trenches into the hedgerow embankments to protect themselves during American artillery and mortar barrages. Furthermore, German commanders linked together their defensive positions with wire communications that allowed them to coordinate the defense of their sector. Snipers also were an important part of the German defense. They were used to protect machine-gun positions against infiltrating Americans and to deliver harassing fire during lulls in the action. Booby traps and mines abounded within the thick vegetation of the hedgerows. Trip-wire explosives were a German favorite. To combat American armor at close range, German infantry used the panzerfaust (a light, portable weapon, fired by one man, that launched an armor-piercing rocket). At longer ranges, Germans engaged American armor with tank main guns, self-propelled guns, and used the legendary 88-mm antiaircraft gun in a ground-defense mode.6

The early fighting in Normandy demonstrated the effectiveness of the German defensive system. American infantry commanders soon realized that normal tactical maneuvers were impossible in the Bocage. Company commanders initially used conventional methods of attack, with two rifle platoons abreast followed in turn by the third rifle platoon and the weapons platoon. However, companies could not deploy and maneuver because of thick vegetation and the compartmentalized nature of the terrain. Platoons were forced to hack their way through the dense vegetation because German defensive fires covered all natural breaks in the hedgerows. As leading attack elements emerged from the hedgerows, they found themselves exposed to almost point-blank German. machine-gun fire. Pinned down in the open in the middle of a well-prepared kill zone, infantrymen were unable to maneuver and continue the attack. Squads returned fire with their own rifles and automatic weapons, but their firepower was not enough to suppress the defenders. American commanders quickly discovered that four or five German defensive positions could pin down an entire infantry battalion and hold up an attack for long periods.7

http://www.cgsc.edu/carl/resources/csi/doubler/doubler.asp#21

[Steiner14]

Thanks for the post Blackcat.

I ran two more test runs which are now also posted here

Interesting, but what are the numbers and the result representing? Losses of the attacker & HMG being destroyed?

[undead reindeer cavalry]

Joch,

i believe it's exactly what most of us would like to see and what we have been talking about for months. i'll requote your quote:

The purpose of the heavy machine guns was to pin down attacking infantrymen in the open

American infantrymen seeking cover and concealment during their advance.

Once pinned down in the open

Pinned down in the open

infantrymen were unable to maneuver and continue the attack

Squads returned fire with their own rifles and automatic weapons, but their firepower was not enough to suppress the defenders.

[Wiggum]

...and thats the issue at the moment.

The supression effect is too low and units recover too fast from "being supressed"...

Also, the moral is recovered too fast in some situations or maybe the moral should drop faster and recover slower overall.