Some thoughts on the effectiveness of the M735 and M774 APFSDS on the glacis armor of T-64A.

[Vanir Ausf B]

The ballistics will be looked at again for the first module. We'll see what comes of that, but I don't expect any changes before then.

Good thread, by the way!

[MikeyD]

There was a reason why everybody quickly transitioned to the 120mm cannon and left the 105mm gun to the museums, gate guardians... and Stryker MGS.

[Centurian52]

I wonder if there is some confusion between the T-64 and T-72. The M774 can get through the frontal composite armor on the T-72 in game without too much difficulty, but has a hard time getting through the frontal composite armor of the T-64. My understanding is that while the T-72 has the same armor layout as the T-64, it is using cheaper materials. Is it possible that the people arguing that the M774 should be getting through the T-64 are in fact looking at evidence that it should be able to get through the T-72?

[The_Capt]

Having followed this, I am not sure it is ballistics problem, it looks more like a targeting problem.  TACAI is programmed to aim for center of mass and in these sorts of tests, wherever that is tends to be a point where the armor is strong.  One way to test this might be to crank up wind speed to see if that has an impact.  That and maybe we could ask for smarter targeting based on crew experience (in fact it might already be in there).

[BeondTheGrave]

2 hours ago, MikeyD said:

There was a reason why everybody quickly transitioned to the 120mm cannon and left the 105mm gun to the museums, gate guardians... and Stryker MGS.

The development of the 120mm cannons was actually super long in coming. The basic lineage of the German 120mm that everyone uses now traces back to the US DELTA program from the late 50s/early 60s. That was a competitor to the 152mm Gun/Missile/Shillelagh thing on the Starship, M551, and MBT-70. It was planned to have semi-guided projectiles and do all kinds of cool stuff. But it just never quite came together right. At the time the velocities and ranges of guns were such that HEAT was thought to be the better choice, an ATGM was just overall more attractive than a rigid penetrator like APDS. During the MBT-70 program, DELTA was introduced as a gun competitor and the FRG received copies of all the technical data (as, after all, they were paying ~40% of R&D costs). They really liked a simplified 120mm version of the gun, but the US was still in the grips of the missile craze and also were very late in picking up on the introduction of the T-64. When they MBT died its ugly death, the FRG played around with refitting their KPZs with the 120mm, then again with the Keller, before finally landing on the Leo 2. That gave them even more time to bake the 120mm into something quite good. In the US, the collapse of the MBT program stymied certain development programs. While the XM1 program broke ground in important ways, ultimately it was actually an austerity program versus the MBT-70 and thats why you see the gun revert back to the more proven and plentiful 105mm.  

So from initiation to fielding, the basic 120mm gun took fifteen(ish) years to land in FRG service, and probably twenty for the US. A good assumption to make is if the US fielded it in the 1980s, development on those lines actually started in the 60s lol. 

[Redwolf]

3 minutes ago, BeondTheGrave said:

When they MBT died its ugly death, the FRG played around with refitting their KPZs with the 120mm, then again with the Keller, before finally landing on the Leo 2.

Keller?

[IICptMillerII]

I just want to reiterate that this is a really good thread.

2 hours ago, The_Capt said:

Having followed this, I am not sure it is ballistics problem, it looks more like a targeting problem.  TACAI is programmed to aim for center of mass and in these sorts of tests, wherever that is tends to be a point where the armor is strong.  One way to test this might be to crank up wind speed to see if that has an impact.  That and maybe we could ask for smarter targeting based on crew experience (in fact it might already be in there).

I tend to agree with Warren on this one. From everything I have seen, I think that CMCW has the ballistics down pretty well. I'm a bit of a nerd when it comes to tank rounds and performance during this era, and to my eye I am not seeing anything happen that is too egregious. 

FWIW I have played a lot of Steel Beasts featuring similar matchups and what happens in that sim seems to mirror what happens in this one. I also know that CM is using numbers that are very close to Steel Beasts, both in ammunition data and armor protection.

I'm not discrediting anything said in this thread though. Right now, my working theory is that there is a bit of observation bias due to the fact that the player is not doing the aiming, and because the player always notices when things go wrong (rounds not penetrating) as opposed to when things go right (rounds punching through). 

I will say though, that I am a bit curious about the armor protection on the T-64A. It is possible that it might be a bit beefier than it should be when it comes to sabot rounds. I will point out that all other anti tank weapons seem to perform as expected against the T-64 (dragon, TOW, LAW, etc) which also leads me to believe that things are in fact working as designed, but it is still worth looking in to. With that said, the T-64A as is needs an update. There should be a T-64A (1980) version to reflect upgrade packages the Soviets applied (smoke launchers being one of the most obvious), just like there is a T-72A and a T-72A (1980). This is coming with the module. Not sure how much, if at all it will affect the armor protection, but seeing that the T-64 will be getting a bit of a workover for the module, I think it will be worth looking into its armor protection. 

[BeondTheGrave]

1 hour ago, Redwolf said:

Keller?

Oops, typo. I meant Keiler, which was the German equivalent to the XM803. The concept was basically to take the MBT-70, which was generally unacceptable to the FRG, and turn it into something they could take. So it was rearmed, reengined, etc. On paper the program started in 1970(IIRC) and lasted into the mid-1970s when it eventually tapered off, but it was only really hot for about a year or two. Very quickly the Germans decided that the MBT-70 was a fundamentally flawed program and that they had to basically restart the design process, so they did and that led into the Leo2 we all know and love. BUT, confusingly, Keilers were kept around as testbeds (I think maybe 2 were built?) And so there is a bit of variation in equipment and activities. 

[FinStabilized]

7 hours ago, MikeyD said:

There was a reason why everybody quickly transitioned to the 120mm cannon and left the 105mm gun to the museums, gate guardians... and Stryker MGS.

Sure. But the Soviets also felt they needed to improve their armor during this period. Also I dont know if I would call the transition quick. M1A1's with 120mm guns did not start showing up in large numbers until 87-88.

 

3 hours ago, IICptMillerII said:

FWIW I have played a lot of Steel Beasts featuring similar matchups and what happens in that sim seems to mirror what happens in this one. I also know that CM is using numbers that are very close to Steel Beasts, both in ammunition data and armor protection.

I posted screenshots that show that what happens in the two games does not agree.  M735 will penetrate the T-64A glacis no problem in Steel Beasts. It does not in CM. Part of why I think this is weird is because in other titles CM and SB line up extremely well, such as in Black Sea or Shock Force 2.

 

 

3 hours ago, IICptMillerII said:

ight now, my working theory is that there is a bit of observation bias due to the fact that the player is not doing the aiming, and because the player always notices when things go wrong (rounds not penetrating) as opposed to when things go right (rounds punching through). 

That is why I did over 100 tests, so we would have a sample size and not just random anecdotal perception. And several other people did tests with similar results. M735 only very very rarely gets through the glacis at 1km. And M774 struggles agaisnt it despite the fact that we know for certain it could get through at triple the distance.

 

 

 

 

14 hours ago, Vanir Ausf B said:

The ballistics will be looked at again for the first module. We'll see what comes of that, but I don't expect any changes before then.

Good thread, by the way!

 

Thanks I very much appreciate the confirmation that its going to be looked at!

Edited November 10, 2021 by FinStabilized

[IICptMillerII]

1 hour ago, FinStabilized said:

Thanks I very much appreciate the confirmation that its going to be looked at!

I appreciate the way you have handled and presented your argument!

I've started an internal discussion about this and will be looking more into it myself as well. I can't promise anything will change, but I can say that this will be looked into. Thanks again!

[Combatintman]

On 11/10/2021 at 6:24 PM, BeondTheGrave said:

The development of the 120mm cannons was actually super long in coming. The basic lineage of the German 120mm that everyone uses now traces back to the US DELTA program from the late 50s/early 60s. That was a competitor to the 152mm Gun/Missile/Shillelagh thing on the Starship, M551, and MBT-70. It was planned to have semi-guided projectiles and do all kinds of cool stuff. But it just never quite came together right. At the time the velocities and ranges of guns were such that HEAT was thought to be the better choice, an ATGM was just overall more attractive than a rigid penetrator like APDS. During the MBT-70 program, DELTA was introduced as a gun competitor and the FRG received copies of all the technical data (as, after all, they were paying ~40% of R&D costs). They really liked a simplified 120mm version of the gun, but the US was still in the grips of the missile craze and also were very late in picking up on the introduction of the T-64. When they MBT died its ugly death, the FRG played around with refitting their KPZs with the 120mm, then again with the Keller, before finally landing on the Leo 2. That gave them even more time to bake the 120mm into something quite good. In the US, the collapse of the MBT program stymied certain development programs. While the XM1 program broke ground in important ways, ultimately it was actually an austerity program versus the MBT-70 and thats why you see the gun revert back to the more proven and plentiful 105mm.  

So from initiation to fielding, the basic 120mm gun took fifteen(ish) years to land in FRG service, and probably twenty for the US. A good assumption to make is if the US fielded it in the 1980s, development on those lines actually started in the 60s lol. 

Despite inventing and having numerous examples of the marvellous L7 105mm gun, the L11 120mm gun was fielded with the Chieftain by the British Army from 1968.

[Sgt.Squarehead]

Pretty sure both Conqueror (1955-1966) & M103 (1957-1974) had 120mm guns, indeed I know they did. 

It was the 120mm armed MBT, as opposed to Heavy Tank, that took a while to arrive.

[Combatintman]

26 minutes ago, Sgt.Squarehead said:

Pretty sure both Conqueror (1955-1966) & M103 (1957-1974) had 120mm guns, indeed I know they did. 

It was the 120mm armed MBT, as opposed to Heavy Tank, that took a while to arrive.

Yes they did but the thing needed separate loaders for the charge and the round apparently.

[Sgt.Squarehead]

Indeed, very unwieldy, but deemed neccessary because of the IS-3 & T-10.....I'd love to see an older Cold War with all of these heavies and some of our old friends from WWII too. 

[BeondTheGrave]

23 minutes ago, Sgt.Squarehead said:

Indeed, very unwieldy, but deemed neccessary because of the IS-3 & T-10.....I'd love to see an older Cold War with all of these heavies and some of our old friends from WWII too. 

Indeed. I think a Pentatomic module could be really cool, especially if BFG ever comes up with a good solution to NBC warfare. A little earlier, but I think a 1950s era module with a mix of WWII and super-WWII tech could be really fun too. Less of a need to solve the NBC problem as well, for all intents and purposes in 1950 US nukes were going to be held back for strategic bombing due to their numbers, or lack there of. No gen-1 ATGMs or newer heavies though. 

RE the M103 youre totally right that its gun predates even what I had mentioned in my post. To be honest IDK how that fits into the lineage. Most of the materials I've read suggests that DELTA, which would grow and evolve into the 120mms we have today, was itself a whole new thing. But I cant tell if its because of the crazy ammunition they were proposing, or if its because the gun itself had some unique features that the M103 didn't have. Off the top of my head, the M103 has a much bigger turret ring than the MBT-70 doesn it? Could be manufacturing the same gun & handling characteristics with a shorter recoil? An interesting point though to be sure. 

[Artkin]

On 11/15/2021 at 2:56 PM, Sgt.Squarehead said:

Indeed, very unwieldy, but deemed neccessary because of the IS-3 & T-10.....I'd love to see an older Cold War with all of these heavies and some of our old friends from WWII too. 

DITTO, Do it in CMCW which has the libraries to handle converted maps from every single title. 

Also we have the benefit of playing these battles on the fastest performing CM. 

[Amedeo]

On 11/15/2021 at 8:56 PM, Sgt.Squarehead said:

Indeed, very unwieldy, but deemed neccessary because of the IS-3 & T-10.....I'd love to see an older Cold War with all of these heavies and some of our old friends from WWII too. 

To see Soviets heavies, it would be enough to extend the game timeframe to 1976, since that was the year when T-10s, IS-3s (and IS-2Ms too) were retired from the Group of Soviet Forces in Germany.

But I can understand why your would like to see some Conqueror vs IS-3 matchup... although an attack lead by Leopard 1s against defending IS-2s would also be fun to play.

[MikeyD]

I recall reading that the US struggled with nagging problems with its 105mm APFSDS rounds that didn't really get ironed out until introduction of the M900 round in 1989. The M900 was authorized for M1 series tanks only. Firing it from other tanks (or older guns) was risking catastrophic breech failure or recoil damage. That round was operating at the outer envelope of what that gun was capable of.

[THH149]

I think this reveals the current state of mind of the CM CW team re the M735.... from the Steam CMCW manual:

M60A1 (RISE+) Patton
In the late 1970s, the gun's mechanical ballistic drive had its cam updated to allow for the newer, more accurate M735 Armor-Piercing Fin-Stabilized Discarding Sabot (APFSDS) round. With up to 410 mm RHAe of armor penetration, the M735 was a major improvement over the earlier M728, but the round was still underpowered against the frontal armor of advanced Soviet tanks such as the T-64B, T-72A, and T-80B, sometimes significantly so.

 

[IICptMillerII]

Quote

this reveals the current state of mind of the CM CW team re the M735.

To be clear, we are looking into the effectiveness of these rounds vs the T-64A hull armor. 

[dpabrams]

12 hours ago, IICptMillerII said:

To be clear, we are looking into the effectiveness of these rounds vs the T-64A hull armor. 

Check your messages Cpt.