KGMU effectiveness

[flavnet]

Hi everyone. I have tried several times to use this weapon with the Su-25 with very disappointing results. I used it, for example, against a western tank column (Abrams, Leopard and Challenger). I aligned the aircraft to the column and dropped the contents of the six canisters along the column with complete coverage of the column and maximum effect. The result was disappointing. Only one Abrams (out of 12 tanks) was destroyed, all others received no damage (or minimal damage). Out of curiosity, I tried to perform the same mission with an F-15E armed with 6 CBU-97. The attack was devastating: all the tanks were destroyed (some on the first pass, others exploded later as a result of the damage). I believe the lethality potential of KMGU content is grossly underestimated.

[razo+r]

Which submunition did you try it with?

[flavnet]

KMGU-2 with anti-tank submunition (HEAT/AP).

Edited July 16, 2023 by flavnet

[Badger1-1]

On 7/16/2023 at 5:39 PM, flavnet said:

Hi everyone. I have tried several times to use this weapon with the Su-25 with very disappointing results. I used it, for example, against a western tank column (Abrams, Leopard and Challenger). I aligned the aircraft to the column and dropped the contents of the six canisters along the column with complete coverage of the column and maximum effect. The result was disappointing. Only one Abrams (out of 12 tanks) was destroyed, all others received no damage (or minimal damage). Out of curiosity, I tried to perform the same mission with an F-15E armed with 6 CBU-97. The attack was devastating: all the tanks were destroyed (some on the first pass, others exploded later as a result of the damage). I believe the lethality potential of KMGU content is grossly underestimated.

You cant compare the two. You could use the Mk20s (CBU100) and then compare. The CBU 97 works differently, it has a IR Sensor and coordinates with the other seekers to maximize damage(iirc) and can actually aim at the tank.

 

The KMGU uses either PTAB 1M or 2.5 and these are not aimed but are dumb bomblets. In DCS with no real damage model in place it needs a perfect hit to destroy a tank.

[PawlaczGMD]

Bump. A similar issue is present with the RBK cluster containers. Despite perfect direct hits, it rarely does any damage to armor, regardless of submunition type. Heavy HEAT/AP performs the worst of them all if anything... I am only able to destroy trucks reliably with these. An APC/IFV has very low chance of getting damage from the dispenser, and almost no chance from RBKs. MBTs- forget about it. 

 

I think it's likely that the armor penetration of the submunitions is severely underestimated. Because if it was about hit probability, trucks would also not be getting destroyed. So the submunitions are hitting, but doing no damage.

Edited November 27, 2023 by PawlaczGMD

[PawlaczGMD]

On 7/24/2023 at 7:35 AM, Badger1-1 said:

You cant compare the two. You could use the Mk20s (CBU100) and then compare. The CBU 97 works differently, it has a IR Sensor and coordinates with the other seekers to maximize damage(iirc) and can actually aim at the tank.

 

The KMGU uses either PTAB 1M or 2.5 and these are not aimed but are dumb bomblets. In DCS with no real damage model in place it needs a perfect hit to destroy a tank.

Comparing practice hits vs trucks and tanks, the submunitions must be getting hits. Because if I drop an RBK on a truck, I will always kill it. But dropping it even on a BTR 90: never. They have roughly the same size, so the likelihood of a hit should be the same. So it must be that the clusters are hitting, but not doing damage.

Looking at some sources, these PTABs should be able to pen 100-200 mm of RHA, so way more than a BTR has anywhere, and definitely on the roof, where they should be most likely to hit.

[flavnet]

HI! I tested the mission of attacking a column of Russian armored vehicles made up of six BTR-82s followed by six T-90s with an F-15E armed with 13 MK-20s. The result, as Badger1-1 had predicted, was that the BTR-82s were immediately destroyed but, despite being within the submunition trail, the T-90s remained unharmed.
Therefore, the lethality of the KGMU-2 is similar to that of the MK-20, while, unfortunately, in DCS there is no Russian counterpart of the CBU-97 to equip the Su-25 and make it an effective anti-tank weapon.

[Dragon1-1]

DCS damage model for ground units is unfortunately too primitive to represent thin top armor on most tanks. IRL, the small HEAT submunitions of Mk20 and KGMU-2 (as well as RBKs) work well enough against anything that doesn't have ERA on top of the turret, and with a lucky hit, even on things that do have it. In their current state, those weapons aren't effective tankbusters.

[WinterH]

16 hours ago, Dragon1-1 said:

DCS damage model for ground units is unfortunately too primitive to represent thin top armor on most tanks.

I am not sure about that tbh. I'd agree some years ago, but it seems this was improved down the line somewhere. When I've tested GSh-23 on various aircraft about 3 years ago, whether I hit a vehicle from front/side/rear/top did matter significantly. Not only that, the impact angle of the shells mattered at least as much. I'll update this post later with its video from back then. 

So in this case it may well be that the penetration from the submunitions being perhaps underestimated. Though this itself should be easy to check from their Luas, there's a data mining repository of DCS weapons somewhere on github that's updated with every patch.

As for the CBU-97, like others have said it isn't an apples to apples comparison because its submunitions are "guided" and will almost all hit the available targets in their area of coverage. Russia is supposed to have a similar submunition, named SPBE-D but don't know if it was made avaliable in widespread use, and even then, when. In any case, we don't have it in DCS yet. I even think it's in files somewhere, just not available in editor even for recent AI planes I think, and certainly aren't avaliable on any player flyable aircraft either. 

However, I think CBUs without such sensor equipment should still be deadly on most tanks, but right now they are very underwhelming on anything beyond IFVs.

Edited November 28, 2023 by WinterH

[Dragon1-1]

There's also one more thing: CBU-97 is a kinetic penetrator (EFP), while the others are HEAT. It's possible that HEAT is poorly modeled in DCS. Now, the CBU-97 is generally a vastly more effective weapon than older antitank cluster, but the Mk20 is definitely capable of disabling older tanks IRL. A hit anywhere on the engine or the top of the turret would take anything without topside ERA out of action.

[PawlaczGMD]

16 hours ago, flavnet said:

HI! I tested the mission of attacking a column of Russian armored vehicles made up of six BTR-82s followed by six T-90s with an F-15E armed with 13 MK-20s. The result, as Badger1-1 had predicted, was that the BTR-82s were immediately destroyed but, despite being within the submunition trail, the T-90s remained unharmed.
Therefore, the lethality of the KGMU-2 is similar to that of the MK-20, while, unfortunately, in DCS there is no Russian counterpart of the CBU-97 to equip the Su-25 and make it an effective anti-tank weapon.

I've found that the KGMU is a lot more effective than the heavy AP/HEAT from an RBK (PTAB 10.5M). These ones can't even damage BTRs. 

So the state of Russian cluster munitions is really poor...

KGMU is only useful against trucks and maybe BTRs. I've had mixed results where sometimes I can kill 4 BTRs in a line, sometimes 0. I think that's still underpowered, because by sheer density each BTR must be getting multiple cluster hits, and they should all pen from the top, but let's say this performance is acceptable. 

I suspect that they don't model all the submunitions to save performance, and so the chance of a good hit is smaller than it should be...

RBKs I would say are totally useless in the current state, an iron bomb of equivalent weight is just better in every case. No reason to ever load them.

Edited November 28, 2023 by PawlaczGMD

[Ramius007]

It's lack of splash damage in general, HE cluster munitions, weaker heat warheads and small unguided rockets are underpowered in general, to make effects more realistic, we need to increase splash damage (thare is mod for this) and effects of subamunition on vehicle crew, it's not really difficult to penetrate turret by aerial dropped munition, even older heat bombs, issue is hitpoints based system, with no crew hitpoints

Edited November 28, 2023 by Ramius007

[PawlaczGMD]

5 minutes ago, Ramius007 said:

It's lack of splash damage in general, HE cluster munitions, weaker heat warheads and small unguided rockets are underpowered in general, to make effects more realistic, we need to increase splash damage (thare is mod for this) and effects of subamunition on vehicle crew, it's not really difficult to penetrate turret by aerial dropped munition, even older heat bombs, issue is hitpoints based system, with no crew hitpoints

 

That's all true, but we're talking about HEAT submunitions here. This is a shaped charge that does not have an area of effect anti-armor damage, so we're talking about direct hits that don't penetrate. I think it's an independent issue.

[WinterH]

Just now, PawlaczGMD said:

That's all true, but we're talking about HEAT submunitions here. This is a shaped charge that does not have an area of effect anti-armor damage, so we're talking about direct hits that don't penetrate. I think it's an independent issue.

At first I was going to react the way you did, Ramius does have a point in saying issue is (well at least partially, probably) in hitpoint based damage model: With and unguided cluster bomb, unlike CBU-97 and 105, we probably get few penetrating hits on tanks, and in HP based model small submunitions' damage is not enough on a tank that has lots of them, even when it can penetrate. Well, maybe anyway... still not sure, because the mission log only lists damaging hits, aka those that did penetrate, and as far as I can recall, when I use clusters on tanks I rarely get any "damaged" entry for those, meaning even if they do hit, they didn't penetrate.

This needs some testing to find the real issue/or set of issues.

[PawlaczGMD]

1 hour ago, WinterH said:

At first I was going to react the way you did, Ramius does have a point in saying issue is (well at least partially, probably) in hitpoint based damage model: With and unguided cluster bomb, unlike CBU-97 and 105, we probably get few penetrating hits on tanks, and in HP based model small submunitions' damage is not enough on a tank that has lots of them, even when it can penetrate. Well, maybe anyway... still not sure, because the mission log only lists damaging hits, aka those that did penetrate, and as far as I can recall, when I use clusters on tanks I rarely get any "damaged" entry for those, meaning even if they do hit, they didn't penetrate.

This needs some testing to find the real issue/or set of issues.

Yeah, I also have the damage dialog on, which should show if you do even 1% of damage. This is not the case. Even with the flawed hitpoint system, I would expect any penetrating hit to do non-zero % of damage. I know that even fractional damage registers there. For example, firing the Ka-50 gun at a ship- it will show damage done! So no effect at all when a RBK with heavy HEAT is dropped straight on a tank or BTR is concerning.

[Ironhand]

23 hours ago, PawlaczGMD said:

I've found that the KGMU is a lot more effective than the heavy AP/HEAT from an RBK (PTAB 10.5M). These ones can't even damage BTRs. 

Whether correct or not (I don't know and am not going to research it), the RBK (PTAB 10.5M) disperses in a doughnut shape with the submunitions in a ring around a hollow center. To make matters worse, they tend to clump rather than be evenly dispersed. Dropped at high speed/low altitude you'll get a fairly tight pattern that's roughly 25x15 meters making it tough to kill more than 1 vehicle. Dropped in a steep dive from 5500m altitude, you'll get a more circular pattern 30-40 meters wide. Given that knowledge, you can get, maybe, 2 BTR-80s. You'll get a T-90 if it's unlucky enough to end up under one of those clumps.

TRK files attached.

PTAB BTR-80-Views.trk PTAB MBT T-90.trk

Edited November 29, 2023 by Ironhand

[PawlaczGMD]

1 hour ago, Ironhand said:

Whether correct or not (I don't know and am not going to research it), the RBK (PTAB 10.5M) disperses in a doughnut shape with the submunitions in a ring around a hollow center. To make matters worse, they tend to clump rather than be evenly dispersed. Dropped at high speed/low altitude you'll get a fairly tight pattern that's roughly 25x15 meters making it tough to kill more than 1 vehicle. Dropped in a steep dive from 5500m altitude, you'll get a more circular pattern 30-40 meters wide. Given that knowledge, you can get, maybe, 2 BTR-80s. You'll get a T-80 if it's unlucky enough to end up under one of those clumps.

TRK files attached.

PTAB BTR-80-Views.trk 195.5 kB · 0 downloads PTAB MBT T-90.trk 156.15 kB · 0 downloads

 

Interesting, thanks for the test. Did you notice if the correct nr of submunitions is modelled?

Either way,  it would explain why I can never get a kill on armor...

[Ironhand]

2 hours ago, PawlaczGMD said:

Interesting, thanks for the test. Did you notice if the correct nr of submunitions is modelled?

Either way,  it would explain why I can never get a kill on armor...

I didn't count. However, in other situations where I have counted, the number has always been correct.

I'm uploading short videos made from each TRK. They'll be available later today. I suppose you could pause the video and count. Then you'd know for sure. Each video is less than 1 minute long.

 

BTR-80:

 

MBT T-90

 

Edited November 29, 2023 by Ironhand
Add videos

[WinterH]

Also testing, will do some more but so far:

- Just like Ironhand said above, PTAB 10-5 disperses in a ring shape, leaving a huge mostly safe zone in the middle.

- PTAB 2.5M and PTAB 1M both disperse a lot more uniformly within their coverage area.

- Tested them from a Su-25, and while I'm not 100% sure it isn't me, I feel like with 80% confidence CCRP and even CCIP falls LONG with PTAB 10-5 and PTAB 2.5M

- Dropping with a high-ish CCRP using PTAB 1M ensured that a half decent area was covered, and bomblets fell with a fairly steep, almost perpendicular to the top of the target

- They DID penetrate an Abrams, and did 95% damage with 7 hits

- PTAB 2.5M and 10-50 had less coverage, with 2.5 having a bit more reliable coverage that at least isn't donut shaped.

- With 10-5 it feels like releasing a stick of multiple RBKs is more or less mandatory so the donuts at least somewhat intersect

- Seems, 10-5 kills Abrams with 2-3 succesfull hits.

 

I'll test more, including KMGU, interestingly, sub munitions are named different between KMGU and RBK, not sure if it's significant, but one's called PTAB 2.5KO, and the other PTAB 2.5M, will test KMGU too, as well as other clusters like Mk 20 Rockeye, Belouga, BL755. I recall BL755's bomblets being quite damaging from years back when I was playing around with them on MiG-21.

 

[PawlaczGMD]

11 minutes ago, WinterH said:

 

 

I'll test more, including KMGU, interestingly, sub munitions are named different between KMGU and RBK, not sure if it's significant, but one's called PTAB 2.5KO, and the other PTAB 2.5M, will test KMGU too, as well as other clusters like Mk 20 Rockeye, Belouga, BL755. I recall BL755's bomblets being quite damaging from years back when I was playing around with them on MiG-21.

 

They are different submunitions, the RBKs release elongated bomb-like ones, while KGMUs release spherical ones.

Last time I checked, the Western cluster munitions were quite effective.

 

It would be great to know which combination of cluster type and release profile is the most useful!

[Ironhand]

14 minutes ago, WinterH said:

Also testing, will do some more but so far:…

All very interesting.

[WinterH]

Just tried KMGU and... wow that was super impressive visually, and equally unimpressive effect-on-target wise.

Coverage looks good, at least not donut-like. But maybe bomblets cover the area sparsely. I think this was another case of CCRP being long, but may well be me too, anyway missed the first two vehicles in the line, one of which was that Abrams, but did only 18% damage to T-80U (and overall it's resistance seemed worse than Abrams in other tests), killed Bradley, and did nothing to the M113 that was on its path, maybe missed it wasn't perfectly aligned.

12 minutes ago, PawlaczGMD said:

They are different submunitions, the RBKs release elongated bomb-like ones, while KGMUs release spherical ones.

Last time I checked, the Western cluster munitions were quite effective.

Yeah they were different indeed. And I feel like damage after defeating armor is lower on RBK's 2.5KOs, needs more testing to confirm 

As for Western CBUs, my experience with Rockeyes have been hit-miss, sometimes I got amazing results out of them, other times highly disappointing. But generally seem to do a bit better with them, yes.

Edited November 29, 2023 by WinterH
hooooly mother of typoes

[Ironhand]

2 minutes ago, WinterH said:

…I think this was another case of CCRP being long…

I seem to recall an “official” training mission that advised placing the pipper slightly ahead of the target because of the delay in the bomblets dispensing. But I could be imagining it all.

[PawlaczGMD]

15 minutes ago, Ironhand said:

I seem to recall an “official” training mission that advised placing the pipper slightly ahead of the target because of the delay in the bomblets dispensing. But I could be imagining it all.

Yup, exactly. Release just a bit short, as it takes time for the dispenser to open.

[PawlaczGMD]

Wow that spread pattern is horrible, but it does look intentional...