chieftain tank vs t-62

[Svenne]

Does anybody know how to fight t-62s with chieftains? Seems like no matter what i do chieftain always looses and that t-62s just kills everything in it's path. Like it's super easy to play Iraq, but with Iran i'm struggling hard. Am i supposed to use other weapons to take out the t-62? It's really hard.

[Battleshipfree99]

Originally posted by andrey12345 v2.0:

Unfortunately, this document does not disclose the secret of obtaining 20% for the T-62. And there are some dubious graphs, and everything looks like they were trying to pretend that the M60A1 is at least somehow better than the T-62.

T-62 (before 1975) doesn't have a laser range finder. It's extremely difficult to accurately range a target at 2km by calculating mils or checking target height curve, and score a first round HEAT hit. APFSDS is thus preferred for better hit probability. And that's why I'm curious why the T-62s in SABOW/GTMF always get a first round HEAT landed with no more than 100m of error on 2km. It's almost like they've got laser range finders.

As @archibaldthe1 has pointed out, there seems to be no ranging process in an engagement. Probably the AIs obtains the range with a fixed accuracy? If this is the case, then first round hit is more likely in GT than reality while following shots are less accurate than reality (after obtaining a more accurate range). Since I always find the first round hit probability to be very close to the overall accuracy in GT.

[Toni]

Regarding the "post-penetration effect": HEAT vs APFSDS (against modern armor, late 90s tank gunner info):

1.) APFSDS (DM-33 type)

- APFSDS has a better post-penetration effect than HEAT because the KE-penetrator has a significantly higher mass than a HEAT jet.

- After penetration the KE-penetrator can break up in large fragments (about 1.000 C hot) because of the mechanical stress that is generated while working through thicker armor (when getting clear of the armor after penetration, the stress is released, breaking the penetrator up into fragments). Thinner armor will be penetrated "clean", the penetrator core will not break-up/disintegrate after penetration in such a case, because not enough stress was generated during penetration.

- The KE-penetrator will additionally generate secondary fragments from the armor (ca. 300 C hot).

- Important: The scatter cone of the fragments in case of an APFSDS penetration is wider than in the case of a HEAT penetration.

- Because of (a) the large amount of metal fragments flying around, (b) the high temperature increase and (c) the high pressure increase inside the targeted AFV, the probability of destruction of important parts inside the AFV and the probability of wounding the AFV crew is very high in case of an APFSDS.

2.) HEAT

- The HEAT jet has a lot less mass (the following molten inlay has more mass, but less energy).

- The generated secondary fragments from the armor have about 700 C, but the scatter cone is relatively narrow.

- The pressure increase inside the AFV after a HEAT hit is not high enough to kill the crew (below 8-10 bar)

- The heat/temperature increase after a HEAT hit is also not very high inside the targeted AFV (compared to an APFSDS penetration).

----

In general for both APFSDS and HEAT:

To ignite the ammunition inside an AFV it is necessary to hit the ammunition in the propellant section either directly or through fragments. Diesel tanks are normally not ignited by APFSDS or HEAT hits, ignited will only be leaking, evaporating air-diesel-mix.

Originally posted by Zephyr:

But then again HEAT shells were produced a lot, were really very successful in WWII already and as far as I can tell they are the "gold standard" today when it comes to successful AT shells (basically the most successful shell family) Or am I wrong there?

Hitting with a high-velocity, sub-caliber APFSDS is much easier for several different reasons and "modern" multi-layered composite armor provides 3x more protection against HEAT than normal RHS (by splitting up the energy of the HEAT jet in the softer sub-layers) while not increasing protection against KE that significantly.

And APFSDS post-penetration effect is also better than HEAT, as seen in the tank gunner manual translated above.

[andrey12345 v2.0]

Originally posted by Battleshipfree99:

T-62 (before 1975) doesn't have a proper range finder. It's extremely difficult to range a target at 2km by calculating mils and score a first round HEAT hit. APFSDS is thus preferred for better hit probability.

And his APDS shells are apparently homing, so they don’t need to be aimed?
Sights obviously "act" on all shells in the same way. And if you do not try to pull an owl on the globe, then it is obvious that 20 and 50% for HEAT and APDS for T62 are somewhat fictitious numbers.

Originally posted by Battleshipfree99:

And that's why I'm curious why the T-62s in SABOW/GTMF always get a range with no more than 100m of error on 2km. As @archibaldthe1 has pointed out, there seems to be no ranging process in an engagement. The AIs seems to obtain the range with a fixed accuracy (probably?). If this is the case, then first round hit is more likely in GT than reality while following shots are less accurate than reality (after obtaining a more accurate range).

I don't quite understand what you are talking about. Obviously for a moving target or shooter, the range changes all the time and the error associated with it also changes all the time, including upwards. The error in determining the range depends on a lot of factors, and for optical sights it also depends on the specific gunner.
It is also obvious that when shooting at point-blank range, the range error does not affect the probability of hitting. Ie the graph given with 20% or 50% (for the APDS projectile from the same document) is not correct. And if they are not the right shape, they give the wrong intersection point at a range of 1500 m.

[andrey12345 v2.0]

Originally posted by Toni:

Regarding the "post-penetration effect": HEAT vs APFSDS (against modern armor, late 90s tank gunner info):

- APFSDS has a better post-penetration effect than HEAT because the KE-penetrator has a significantly higher mass than a HEAT jet.

- After penetration the KE-penetrator can break up in large fragments (about 1.000 C hot) because of the mechanical stress that is generated while working through thicker armor (when getting clear of the armor after penetration, the stress is released, breaking the penetrator up into fragments). Thinner armor will be penetrated "clean", the penetrator core will not break-up/disintegrate after penetration in such a case, because not enough stress was generated during penetration.

Only at the beginning of the movement in the armor, and then the penetrator grinds down on the armor with the corresponding projectile underturn. Therefore, this is all true for breaking through thin armor.

https://photos.google.com/u/2/search/_tra_/photo/AF1QipPW-F k n-YAXTCc8UFOzE7autfVO8VoSV7xOYg_A (remove spaces)
Here is a typical trajectory of a 115 mm sub-caliber projectile, as you can see, not only is it grinds off along the way, it also turned almost 90 degrees to the side without breaking through the armor.

Moreover, Soviet APDS shells (which actually hit the Chieftains) have an unpleasant drawback in the form of strong tails, which slow down the projectile when it hits the armor.

So what about the difference in effects, except perhaps a higher temperature for fragments of the core of a sub-caliber projectile. But in fact, for the ignition of what is inside the tank, this difference is not critical, since the temperature of the "cold" cumulative jet is enough to set fire to anything that burns.

[Battleshipfree99]

Originally posted by andrey12345 v2.0:

Originally posted by Battleshipfree99:

T-62 (before 1975) doesn't have a proper range finder. It's extremely difficult to range a target at 2km by calculating mils and score a first round HEAT hit. APFSDS is thus preferred for better hit probability.

And his APDS shells are apparently homing, so they don’t need to be aimed?
Sights obviously "act" on all shells in the same way. And if you do not try to pull an owl on the globe, then it is obvious that 20 and 50% for HEAT and APDS for T62 are somewhat fictitious numbers.

APDS has 1.5~2 times the muzzle velocity of HEAT, a much flatter trajectory. So it doesn't rely on accurate ranging. A T-62 gunner may hit a 2km tank with 1600m zeroed APFSDS but would have to painstakingly adjust for the correct range if he's firing HEAT.

Originally posted by https://thesovietarmourblog.blogspot.com/2015/12/t-62.html#tshs:

Compared to a good optical coincidence rangefinder with a wide optical base length, stadia rangefinding was rather imprecise, especially when used on partially obscured targets. British testing on the stadia rangefinder in the TLS (Tank Laser Sight) installed in Chieftain tanks, identical in form and function to the Soviet type, showed that the average error, taken from three different sets of measurements, reached only 13.7%. The study included three series of tests on partially obscured targets. The average range measurement error for these targets reached 22-37%. When the measurements on the partially obscured targets are omitted from the data set, the average error plummets to merely 5.73%, 9.25% and 7.16%. The mean error across all three sets is 7.38%.

Additionally, a British-Israeli report covering the TSh2B-32 sight gives another valuable data set on the precision of stadia rangefinders. From the table in page 121 of the report (page 64 of the photo album), it is shown that the mean error in ranging tank-shaped screens, broadside tanks, oblique tanks and head-on tanks is 12.77% in the 7x magnification setting, degrading to 14.01% in the 3.5x magnification setting. The results of an analysis of the data were somewhat counter-intuitive. Page 122 of the report (page 65 of the photo album) mentions that the precision of rangefinding against hull-down tanks was surprisingly unaffected by the fact that half of the target was out of sight.

[andrey12345 v2.0]

Originally posted by Battleshipfree99:

APDS has 1.5~2 times the muzzle velocity of HEAT, a much flatter trajectory.
So it doesn't rely on accurate ranging. A T-62 gunner may hit a 2km tank with 1600m zeroed APFSDS but would have to painstakingly adjust for the correct range if he's firing HEAT.

Thank you for repeating what I wrote to you, I'm aware.
Then why is APDS given a 50% chance of 1st hit at 1500m? (in the same doc where for HEAT is given 20%)

[Battleshipfree99]

Originally posted by andrey12345 v2.0:

Originally posted by Battleshipfree99:

APDS has 1.5~2 times the muzzle velocity of HEAT, a much flatter trajectory.
So it doesn't rely on accurate ranging. A T-62 gunner may hit a 2km tank with 1600m zeroed APFSDS but would have to painstakingly adjust for the correct range if he's firing HEAT.

Thank you for repeating what I wrote to you, I'm aware.
Then why is APDS given a 50% chance of 1st hit at 1500m? (in the same doc where for HEAT is given 20%)

50% is the "chance of kill" with first shot, and 30% is the "first round hit" probability on moving targets.

[Battleshipfree99]

Moving T-62, entrenched Chieftain. 2200m+. 3 HEAT fired. 2miss, 1 hit.
https://steamcommunity.com/sharedfiles/filedetails/?id=2939301266
R T-62: 1st round 25m over; 2nd round 25m short.
L T-62: 1st round kill.

This is what we call "laser ranged". lol
25m of first round error on an entrenched tank at 2.2km?

Following tests: Moving T-62 vs Entrenched Chieftain.
2. 2200m; 1st hit. 2nd 5m short, 3rd 30m short.
3. 2100m: 1st 15m over.
4. 2200m: 1st kill.
5. 2100m: 1st hit.
6. 2300m: 1st 35m over.
7. 2100m: 1st 12m short.
8. 2100m: 1st 30m short.
9. 2200m: 1st 30m short.
10. 2200m: 1st 18m over. 2nd 23m over.

[andrey12345 v2.0]

Originally posted by Battleshipfree99:

Originally posted by andrey12345 v2.0:

Thank you for repeating what I wrote to you, I'm aware.
Then why is APDS given a 50% chance of 1st hit at 1500m? (in the same doc where for HEAT is given 20%)

50% is the "chance of kill" with first shot, and 30% is the "first round hit" probability on moving targets.

This is what you "intentioned" as a result of an incorrectly set experiment. And there is no chance of that kill there. Please do not write (and even more so do not repeat when you have been pointed out an error) those things that you do not understand. This is extremely boring, and feels like talking to an AI instead of a human.

[andrey12345 v2.0]

Originally posted by Battleshipfree99:

And that's why I'm curious why the T-62s in SABOW/GTMF always get a first round HEAT landed with no more than 100m of error on 2km.

Because the average error in determining the range to the target at a distance of 2 km using an optical sight with a magnification of 7-9 and range scale is about 5% of the range. 2000 * 0.05 = 100.

Originally posted by Battleshipfree99:

It's almost like they've got laser range finders.

No that's not true. Even for an optical rangefinder (for example, the M60A1 tank), the accuracy of determining the range at a distance of 2 km is about 1%.

I beg you, please do not write nonsense on topics in which you do not understand or do not have knowledge.

[Battleshipfree99]

Originally posted by andrey12345 v2.0:

Originally posted by Battleshipfree99:

And that's why I'm curious why the T-62s in SABOW/GTMF always get a first round HEAT landed with no more than 100m of error on 2km.

Because the average error in determining the range to the target at a distance of 2 km using an optical sight with a magnification of 7-9 and range scale is about 5% of the range. 2000 * 0.05 = 100.

Originally posted by Battleshipfree99:

It's almost like they've got laser range finders.

No that's not true. Even for an optical rangefinder (for example, the M60A1 tank), the accuracy of determining the range at a distance of 2 km is about 1%.

Then what about this source? Not reliable?

Originally posted by https://thesovietarmourblog.blogspot.com/2015/12/t-62.html#tshs:

Compared to a good optical coincidence rangefinder with a wide optical base length, stadia rangefinding was rather imprecise, especially when used on partially obscured targets. British testing on the stadia rangefinder in the TLS (Tank Laser Sight) installed in Chieftain tanks, identical in form and function to the Soviet type, showed that the average error, taken from three different sets of measurements, reached only 13.7%. The study included three series of tests on partially obscured targets. The average range measurement error for these targets reached 22-37%. When the measurements on the partially obscured targets are omitted from the data set, the average error plummets to merely 5.73%, 9.25% and 7.16%. The mean error across all three sets is 7.38%.

Additionally, a British-Israeli report covering the TSh2B-32 sight gives another valuable data set on the precision of stadia rangefinders. From the table in page 121 of the report (page 64 of the photo album), it is shown that the mean error in ranging tank-shaped screens, broadside tanks, oblique tanks and head-on tanks is 12.77% in the 7x magnification setting, degrading to 14.01% in the 3.5x magnification setting. The results of an analysis of the data were somewhat counter-intuitive. Page 122 of the report (page 65 of the photo album) mentions that the precision of rangefinding against hull-down tanks was surprisingly unaffected by the fact that half of the target was out of sight.

[andrey12345 v2.0]

Originally posted by Battleshipfree99:

Originally posted by andrey12345 v2.0:

No that's not true. Even for an optical rangefinder (for example, the M60A1 tank), the accuracy of determining the range at a distance of 2 km is about 1%.

Then what about this source? Not reliable?

Questions of defense technology. Issue #67. Collection of results of studying and testing a full-scale sample of the serial American tank M-60A1. Under the scientific guidance of Ph.D. Idlis V.S. and Ph.D. Potemkin E.K.
Page 27.

Now it's your turn to share sources (not retelling) about the worst accuracy of laser rangefinders :)

[Battleshipfree99]

Originally posted by andrey12345 v2.0:

Originally posted by Battleshipfree99:

Then what about this source? Not reliable?

Questions of defense technology. Issue #67. Collection of results of studying and testing a full-scale sample of the serial American tank M-60A1. Under the scientific guidance of Ph.D. Idlis V.S. and Ph.D. Potemkin E.K.
Page 27.

The original datasheet for the results mentioned above. M60A1 has a 10x coincidence rangefinder, which is better (than 7~9x sights). The British/Israel test also compared the rangefinder on M48 tank with T-55's gunner sight, but give a 4~14% mean error for multiple targets at 1~2.5km.
https://tankandafvnews.files.wordpress.com/2016/02/064.jpg

[andrey12345 v2.0]

Originally posted by Battleshipfree99:

The original datasheet for the results mentioned above.

There is nothing about laser rangefinders. Let me remind you that you stated that an error of 5% is the level of the laser rangefinder.

"And that's why I'm curious why the T-62s in SABOW/GTMF always get a first round HEAT landed with no more than 100m of error on 2km. It's almost like they've got laser range finders."

Please cite the source from where you got it.

In the screenshots you provided, we see that the average range error is 8 and 9% (for magnification 7 and 3.5) times, respectively, for a conventional sight with a range scale on 2,5km. And in that article that you probably didn’t even look at, there is still 4.31% for 2km.
Do you want to say that a laser rangefinder allows to determine the range with an error of 5% only less 2 times better than the sight of the T-62 / T-55 tank and 15% WORSE than the regular sight with range scale of the Chieftain tank? And why then do we need a laser rangefinder at all, lol

[Battleshipfree99]

Ok, I apologize for exaggerating this 5% ranging error as "laser ranged".
But then I saw that 25m HEAT near miss at 2200m, an error of 1.3%, for a 7x/5x stadia rangefinder (T-62). (If we ignore gun dispersion for a moment.)

Originally posted by andrey12345 v2.0:

In the screenshots you provided, we see that the average range error is 8 and 9% (for magnification 7 and 3.5) times, respectively, for a conventional sight with a range scale on 2,5km.

This is one set of data for broadside tank target. Another set for oblique tank target gives 20% error at 2520m.