CMFB patch released

[mOBIUS]

An interesting test shoot was the Soviet tests of Elephant TDs captured after Kursk. They tested sherman 75mm using both M72 and M61 ammunition. M72 failed yet M61 made it through. Perhaps it was face hardened armor? I will have to search to see what the range was.

Edit: It was the side superstructure armor.

That guy running the russian archive site has a sort of bias. He was all excited that 152mm shells broke off a piece of the Elefant's front plate armor. Then it was revealed that the armor was first penetrated at the same location that broke by 75mm L70 APCR. The only tested round that was able to penetrate the 200mm of armor.

 

[NUTTERNAME]

That guy running the russian archive site has a sort of bias. He was all excited that 152mm shells broke off a piece of the Elefant's front plate armor. Then it was revealed that the armor was first penetrated at the same location that broke by 75mm L70 APCR. The only tested round that was able to penetrate the 200mm of armor.

Yeah, he is a Yahoo. I actually wonder if his Russian is that good. He certainly can't read a test report correctly.

http://tankarchives.blogspot.ca/2013/03/sherman-vs-tiger.html

This is his take on the test shoot of 75mm sherman ammunition on a Tiger I side.

This test was performed firing a 75 mm M3 gun from an M4A2 Sherman with M-61 and M-72 rounds. Here are the results: {My bolding}

Side, shell type M-61, distance 400 m. Result: penetration, spalling inside in an area of 300 mm by 300 mm {note: 90 deg dead on shot}
Side, shell type M-72, distance 625 m. Result: penetration, minor spalling on entrance and exit.
Side: shell type M-72, distance 625 m. Result: same as above.
Turret: shell type M-61, distance 650 m. Result: dent 50 mm deep, 140 mm diameter. Penetration of the turret platform. {no real penetration of armor}
Turret: shell type M-61, distance 650. Result: dent 40mm deep, 120mm diameter. {again, no penetration}
Side: shell type M-61, distance 650. Result: Penetration. Shell knocked out a cork-like section of armour. {lower hull side armor 62mm}
Side: shell type M-61, distance 650. Result: same as above. {same}

I have no idea why the Soviets did not use M72 in all cases. Obviously, it would be interesting if the Tiger presented even a 20 degree obliquity. To say that these results show how weak the Tiger was is just stupid. One might suggest the M72 did better against the side 82mm armor?

Edit: And it looks like other Yahoos cut and paste the same 'data' in thier own revisionitic websites...

http://knowledgeglue.com/dispelling-myths-surrounding-m4-sherman/

 

[mOBIUS]

Speaking of Russians using US equipment there is a book about the exploits of a Russain tanker using a Sherman with 76mm. I'm not sure if it primary used M79 ammo or what, but there are a lot of actions. I have a book that has a number of stories and it has a chapter from his book. So there might be something on the effectiveness of the 76mm on various German tanks.

 

[NUTTERNAME]

By the TM9 1907 it could be 1500m-1600m. An average of various M62 data sets from US and British sources gives the 1350m. So somewhere in there.

I DL'd the TM9 1907 from...

http://www.dtic.mil/dtic/tr/fulltext/u2/a955369.pdf

It is from 1950. There is no 55 deg line on the chart for M62A1. I think the 50 degree line shows an anomaly if you compare the transition from the 40 degree line to 45 degree, and then the transition from the 45 to 50 degree line. it should be increasing with angle considerably at the steeper angles.

 

[NUTTERNAME]

http://tankarchives.blogspot.com/2014/12/more-ferdinand-penetration-tests.html

link to Ferdinand tests with 75mm M72 and M61 pics

 

[mOBIUS]

I DL'd the TM9 1907 from...

http://www.dtic.mil/dtic/tr/fulltext/u2/a955369.pdf
.

That's not the original. It is an extract.
Here is a link to the graph
http://www.panzer-war.com/Images/76mm_TM91907.jpg

You might guess who the '-m' is.

You can see how the 76mm is used realistically..
https://www.youtube.com/watch?v=CHqqP_sjtpQ

 

[NUTTERNAME]

Both the 55 degree and 60 degree lines are dashed. There is another basic issue with that graph.

 

[mOBIUS]

At first I didn't think any high angle data was available because the M79 pdfs only had a single case of a 49° impact.
But then searching through my files I found AD301343 Analytical Study of data on Armor Penetration by tank-fired kinetic energy projectiles.
It had high angle test data on the M79 and M62 among various other rounds.

Here is a section:
http://www.panzer-war.com/Files/AD301343j.jpg

The range where the M62 has a ballistic limit of 2592f/s is 24 yards.

 

[NUTTERNAME]

By the TM9 1907 it could be 1500m-1600m. An average of various M62 data sets from US and British sources gives the 1350m. So somewhere in there.

I used your Figure 114 from TM9 1907 and I can scan the results. Basically, taking 52 mm as the thickness (2.05 "), run up to the 55 deg line, cross over to the velocity line M1A1C, drop down to the range of 1000 yards. that is 914 meters. 2280 FPS

Using that same chart, the Panther would be off the chart at 2.6 inch and 55 degrees.

 

[NUTTERNAME]

At first I didn't think any high angle data was available because the M79 pdfs only had a single case of a 49° impact.
But then searching through my files I found AD301343 Analytical Study of data on Armor Penetration by tank-fired kinetic energy projectiles.
It had high angle test data on the M79 and M62 among various other rounds.

Here is a section:
http://www.panzer-war.com/Files/AD301343j.jpg

The range where the M62 has a ballistic limit of 2592f/s is 24 yards.

I guess gun depression might have to be figured in?

 

[mOBIUS]

I used your Figure 114 from TM9 1907 and I can scan the results. Basically, taking 52 mm as the thickness (2.05 "), run up to the 55 deg line, cross over to the velocity line M1A1C, drop down to the range of 1000 yards. that is 914 meters. 2280 FPS

That is correct. If the armor quality is taken into account (assuming German quality of 269BHN) vs. 237 of the US standard multiply the armor thickness by 1.07.

 

[NUTTERNAME]

That is correct. If the armor quality is taken into account (assuming German quality of 269BHN) vs. 237 of the US standard multiply the armor thickness by 1.07.

Yes, that would reduce the range further. i will do some tests with the demo and see if I can get a maximum range on the lower hull of the Jgdpnzr IV/70 when getting hit by M62. It seems that once they are targeted, that area is always hit in short order. People say the same for the game regarding the Panther. Actually, the Jgdpzr IV has a lower ground clearance (I think), than the Panther. So, not only is it a smaller lower hull area, it is also lower to the ground!

I suppose you have read this, but I will post it here to demonstrate just how incredibly geeked out some grogs actually are. I should find my Matrix password and update the Pzgr 39 thread....there is a good one I just read...

http://www.dtic.mil/dtic/tr/fulltext/u2/a955277.pdf

 

[mOBIUS]

You can order hard copies of TM9-1907 from here:
http://www.military-info.com/mphoto/P108b.htm

 

[NUTTERNAME]

Testing of the Jgdpzr IV/70 (late) in the game showed the lower hull to be vulnerable to 76mm M62 fire at 1300 meters. This was with an obliquity angle of about 15 degrees. Giving a larger obliquity gave some protection but still there was spalling, of course this would preclude the Jgdpanzer from using its own main gun.

The upper hull, and superstructure hull do not show penetrations.

It might be possible to test even longer range fire with orthogonal shots given that the demo has some open terrain.

I suppose the next question would be "How vulnerable is the sherman tank types from the front to 75mml70 fire"? In these long range duels, the sherman take some hits.

 

[mOBIUS]

Also some interesting original sources this page:
http://forum.warthunder.com/index.php?/topic/312697-british-guns-penetration/page-4

 

[mOBIUS]

Testing of the Jgdpzr IV/70 (late) in the game showed the lower hull to be vulnerable to 76mm M62 fire at 1300 meters.

In real terms PCO gives vulnerability to around 1500m. In terms of game units it is around 1000. Though the 50% penetration distance is 870m or 580 game units.

I suppose the next question would be "How vulnerable is the sherman tank types from the front to 75mml70 fire"? In these long range duels, the Sherman take some hits.

That really is the way to measure vulnerability, the relative distance between the range it can Ko the opponent vs. the range he can ko you. And the time it takes to close the gap. It then doesn't matter if the ranges are compressed or not.

 

[NUTTERNAME]

Also some interesting original sources this page:
http://forum.warthunder.com/index.php?/topic/312697-british-guns-penetration/page-4

The American gun data listed in post #67 seemed to be in agreement with what I am saying. I don't see any data that says anything like the ranges you were saying earlier? The TM9 1907 chart works 'backwords' in that you can take 90mm and go up to the 30 degree line, go to the left and get the velocity, and drop down to the 1000 yard line.

It is interesting in another post that they state M72 ammo was for homog. armor and M61 was for FH. Someone should translate or post a better scan of that data.

 

[NUTTERNAME]

Post #65 shows the German 75mm KWK 40 as 2526 FPS. That is 770 M/s. thought i wouldn't catch that????

 

[NUTTERNAME]

On the M18 Hellcat...The Soviets said...

The gun has good precision. At a range of 1200 meters, average horizontal deviation is 0.16 meters and vertical deviation is 0.1 meters.
The muzzle velocity of the AP-tracer shell is 803 m/s.
The angle of flight of the AP shell is negative: -3.6 degrees.

http://tankarchives.blogspot.com/2014/03/lend-lease-impressions-m18-hellcat.html

hard to really tell what that means...but if it means the descent angle, or it means the flight attitude...it would mena it would have an issue when striking the lower hull 'back swept' armor of panther's , etc.

 

[mOBIUS]

On the M18 Hellcat...The Soviets said...
http://tankarchives.blogspot.com/2014/03/lend-lease-impressions-m18-hellcat.html

hard to really tell what that means...but if it means the descent angle, or it means the flight attitude...it would mena it would have an issue when striking the lower hull 'back swept' armor of panther's , etc.

I don't know what that means either. At 1200m my ballistic program gives a .667° descent when fired at +.6°. Rexford has the descent of .7°.