CMFB patch released

NUTTERNAME

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This is what I get...a "Forward Top Hit". Again, the awful Battlefront low obliquity modeling rears its head. I made sure this sherman was at 0 degrees when looking directly at its front, and more importantly, from the side. To get a penetrating hit like this is not possible.

View attachment 53703
 

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Edit: i believe a PAK 40 could penetrate a sherman glacis at 1100 meters given the Yugo test data. I am not that sure about the actual penetration criteria, I would suppose getting light through, or perhaps a mix of penetrations and partials. But, in any case, I would expect the 'panther gun" to do better. Stay tuned....
The Yugo penetration is said to be a 50% penetration criteria. Probably similar to the US Naval criteria.
 

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At 1600 meters or so, there are mostly partial penetrations on the front hull of the shermans. These can cause casualties. There are actually turret penetrations or as the game calls them "weapons mount" penetrations at this range.I will look for a longer range but it depends on that map. In these slugfests, any AFV taking hits, even if bounced, take a loss of subsystems. In many cases, they are out of the fight.

It would seem that many of the slugfests I have seen playing the AI come from the reverse slope positioning of the shermans by the scenario designer. The sherman armor will bounce the AP it seems at 1100-1200 meters. I will test that in 2 player hotseat. I would have to guesstimate the actual ground slope element. Maybe take a screenshot and open in Paint. Since the game does not model gun depression limits, it can be a gamey tactic.

The only workaround for the Jgdpzr IV/70 mismodeled (IMO) lower front hull armor is to try and get some partial hull down status for these AFV. The game does not make this easy and it takes more busy-work which is what the game does not need. It is actually somewhat easy for a driver to guage the weapon height on his own Jgdpzr (IRL) since his vision device is at the same level as the gun (much like the StuG).

The game models some weird misses in my opinion. Initial shots being comically overshot and flying overhead like the gun was set for 8000 yds. At 1600 meters, I noticed that dispersion of the L70 gun did not guarantee a follow on shot being another hit in some cases. The shermans, both 75mm and 76mm have no trouble getting on target at 1600 meters also.

Probably one of the better demo scenarios. The awful thing is the graphics for the plowed fields. It's like an astigmatism nightmare. It really hinders getting a terrain comprehension or bearings in some cases.
 

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An interesting late war document.

http://www.matrixgames.com/forums/upfiles/21308/698C7F8A9BF8455BB31FE921123E7C69.jpg

A PAK 40 even at 2600 FPS muzzle velocity would only be 2400 FPS at 450 yards or so (?). The KWK muzzle velocity is probably a mistake and the 2300 FPS should have been 2500 FPS. The Panther gun would be about 1450 yards for 2400 FPS. So using fig. 2 from...

http://www.dtic.mil/dtic/tr/fulltext/u2/492002.pdf

...for 269 BHN, the Panther gun should penetrate the glacis of the sherman. That is, use the 47 deg...cos 47 deg is about 0.7 line, go up and intersect, and read 3.1 inch or 78 mm, more than enough. I will try to bring the shermans in closer and test at 1450 yards (1325 meters) again. The Panther gun should be penetrating the sherman glacis since it is not even 269 BHN.

http://www.matrixgames.com/forums/upfiles/21308/698C7F8A9BF8455BB31FE921123E7C69.jpg
 

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...for 269 BHN, the Panther gun should penetrate the glacis of the sherman. That is, use the 47 deg...cos 47 deg is about 0.7 line, go up and intersect, and read 3.1 inch or 78 mm, more than enough.
Unlike the US the Germans didn't normalize their penetration figures to a single standard armor hardness but tests vs. different levels of armor hardness depending of the thickness. Which would be really convenient if we had German guns firing at German tanks.
However, this makes it rather more difficult to normalize data sets between different nations.

Example of different armor in German tests:
http://www.panzer-war.com/Images/75xxxx.jpg
 
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Unlike the US the Germans didn't normalize their penetration figures to a single standard armor hardness but tests vs. different levels of armor hardness depending of the thickness. Which would be really convenient if we had German guns firing at German tanks.
However, this makes it rather more difficult to normalize data sets between different nations.

Example of different armor in German tests:
http://www.panzer-war.com/Images/75xxxx.jpg
That is what makes...

http://www.dtic.mil/dtic/tr/fulltext/u2/492002.pdf

...somewhat unique. It is sort of a reverse engineered test of sorts. One can look at the graphs and see what a PAK 40 (or any German 7.5 cm weapon firing a PzGr 39 projectile that is travelling at 2400 FPS) can do to a Panther, for example. Or other part of AFV given the BHN and thickness and slope. Please review the graphs and please note the spacing of the angle on the top of the graphs. As slope is increased, the spacing is very non-linear. the US graphs have made a mistake as far as dashed line 'projections' in the 55+ deg range IMO.

The US use of cast armor on many shermans (very soft~210 BHN) shows a serious lack of protection. One of the goals of the test seems to be "Can better armor (BHN) give equal protection and save weight (be thinner)?"...when it is obvious that better and thicker armor is needed, especially since the panther gun is much more powerful than a PAK 40. If anything, the test shows just how well engineered the PzGr 39 was and if anything, the US should have been already comparing it's M61 and M62 projectiles to it.

I will do a test to move the shermans closer to the L70 guns till I can get consistent front hull penetrations.
 

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Another one of those odd hit placements. Evidently ricocheting off the rear belly armor into the ground. Jgdpzrs are 1200 meters away.

View attachment 53747
 

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That is what makes...
http://www.dtic.mil/dtic/tr/fulltext/u2/492002.pdf
...somewhat unique. It is sort of a reverse engineered test of sorts. One can look at the graphs and see what a PAK 40 (or any German 7.5 cm weapon firing a PzGr 39 projectile that is travelling at 2400 FPS) can do to a Panther, for example. Or other part of AFV given the BHN and thickness and slope. Please review the graphs and please note the spacing of the angle on the top of the graphs. As slope is increased, the spacing is very non-linear. the US graphs have made a mistake as far as dashed line 'projections' in the 55+ deg range IMO.
Those tests are on small scale .30cal models. Full scale tests are less definite.
http://www.dtic.mil/dtic/tr/fulltext/u2/310002.pdf
http://www.dtic.mil/dtic/tr/fulltext/u2/a954243.pdf
http://www.dtic.mil/dtic/tr/fulltext/u2/a955289.pdf
http://www.dtic.mil/dtic/tr/fulltext/u2/473866.pdf
 

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Those tests are on small scale .30cal models. Full scale tests are less definite.
My impression is that there is no concerted directed effort and perhaps Navy and Army 'politics' going on. Each had Senior Physicists and programs.

I have to chuckle when reading something like this...

SUMMARY
The subject tests were conducted at 200, 300, and 400
obliquities with 3" M62 capped projectiles at e/d values of 1.01
(370 STS), and 1.39 (410 Class B). The plates were heat treated
over a range of tensile strength from 110,000 psi to 225,000 psi.
Owing to wide variations in type of projectile failure and
to plate non-uniformity, no general statement can be made
regarding the optimum hardness of the subject 3" armor under
the test conditions described, and no consistent effects on
ballistic limits of variations in obliquity or tensile strength
were noted
. However, the optimum hardness of the 4" ermor appears
to be in the neighborhood of 150,000 psi for the 200 and 300
obliquity tests.
The variations in ballistic limits are qualitatively analysed from the standpoint of the energy requirements for
plate and projectile failures which, in turn, were observed to
depend on the plate tensile strength.
...I guess it never occurred to them that the projectiles themselves were not uniform? Basically, they were chasing their tails? Cheap Chevy crap 62 projectiles...?
 

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My impression is that there is no concerted directed effort and perhaps Navy and Army 'politics' going on. Each had Senior Physicists and programs.

I have to chuckle when reading something like this...



...I guess it never occurred to them that the projectiles themselves were not uniform? Basically, they were chasing their tails? Cheap Chevy crap 62 projectiles...?
They didn't stand up to head-on collisions. :)

Also you have check captures from pdfs for OCR errors.
 
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Unlike the US the Germans didn't normalize their penetration figures to a single standard armor hardness but tests vs. different levels of armor hardness depending of the thickness. Which would be really convenient if we had German guns firing at German tanks.
However, this makes it rather more difficult to normalize data sets between different nations.

Example of different armor in German tests:
http://www.panzer-war.com/Images/75xxxx.jpg
Yes, the Germans appear to be varying the curves to introduce the varying hardness. But, given the velocity under question in the US test

http://www.dtic.mil/dtic/tr/fulltext/u2/492002.pdf

And using Fig. 2, primarily the 269 graph and the 320 BHN graphs, there is a comparison that can be made. The German graph shows about 100mm penetration for 730 M/s (roughly 2400 FPS). I am not sure but think the German graph shows 30 degree sloped armor (?), the hardness shown in the German graph is right between the 95-105 Kg/mm2 region (you anoted 275-305 BHN). The US 269 BHN graph shows about 4.4 inches penetration at 30 deg or 112 mm. The 320 BHN appears to be about 3.6 in. or 92 mm. The data appears to be very comparable in this region?
 

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Yes, the German graph is for armor at 30°.

I came across a baffling graph (I think it's German) of 50mm APC showing better penetration for a given velocity for the earlier Pzgr. shell than the Pzgr. 39. But then the old shell leveled out and was surpassed by the pzgr 39. at about 800m/s. Sorry, I could be wrong on that number, I'm not near my home computer right now.
 
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I came across a baffling graph (I think it's German) of 50mm APC showing better penetration for a given velocity for the earlier Pzgr. shell than the Pzgr. 39. But then the old shell leveled out and was surpassed by the pzgr 39. at about 800m/s.
http://www.panzer-war.com/Images/50mmvs50mm.jpg

Here is the graph. It changes at around 660m/s but that is about a range of 650m for the 50mm/L60. It was hiding in plain sight as I had it all along, though I edited it to just show the 50mm shells.
So the L42 changes preference at ~25m while the L60 it is ~650m. There is a big difference in the penetration of the shells that I haven't seen in any tabular data.
 
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http://www.panzer-war.com/Images/50mmvs50mm.jpg

Here is the graph. It changes at around 660m/s but that is about a range of 650m for the 50mm/L60. It was hiding in plain sight as I had it all along, though I edited it to just show the 50mm shells.
So the L42 changes preference at ~25m while the L60 it is ~650m. There is a big difference in the penetration of the shells that I haven't seen in any tabular data.
It is somewhat the same dilemma that the Sherman 75mm had with the M72 or M61 ammunition. That is, when attacking homogenous armor, the M72 would have been preferable. Likewise, the later capped PzGr 39 for the 5,0 cm guns probably did better against FH armor if compared to the earlier 5,0 cm PzGr projectile.

Notice that the later 5,0 cm PzGr 39, like the 7,5 cm PzGr 39 for the Panther and L48/L46 weapons, has a two part main bolt in addition to the hardened cap. I believe there might have been another model with a BC? In any case, the Germans gave up on this 5,0 cm projectile and really focused on the 7,5 cm/8,8 cm weapons late war.
 

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I compared the 50mm Pzgr 39 graph line to that found in the BIOS data graph and it's an exact match. So there is confirmation on the 39 data. I have to keep search for a match to the early round.
 

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I compared the 50mm Pzgr 39 graph line to that found in the BIOS data graph and it's an exact match. So there is confirmation on the 39 data. I have to keep search for a match to the early round.
GL with that. i would like to see some real data on the 50mm weapons. Threads like this one below...

http://community.battlefront.com/topic/53728-t-34-and-kt-vulnerability-issue-solved-was-narrow-turret-front/?page=2

..don't cite much new stuff.

I read reports regarding the AP40 that state the L42 weapon could not fire it or it was defective/ineffective. German manuals certainly state that the AP and APC were listed as standard in early 1943 for the 5,0 cm weapons.
 

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John Salt put out a pdf of many gun penetration data taken from many book sources. It now looks like many authors, especially UK authors, had taken the same data from the BIOS report. Or, they could of used 'Die Vorgange beim Beschuf von Panzerplatten', which has the same 50mm data. I would of liked some original War Office test data.
 

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That's a pretty old post and the next page (#21) Rexford changes the data to account for armor quality. I'm sure he probably changed it many times since then.
Yes, but the newer posts are pathetic. There was a good thread regarding the JSII armor and a guy was measuring a specimen. To his credit, he was not a CM 'regular' (or irregular as I see them). I was surprised to see that the Soviets used hard durometer isolation mounts (rubber) under the mantlet.

It would be interesting to know what a PAK 40 shoot against a Panther would reveal. I suspect the bow armor would be tough but the turret and lower hull might be more vulnerable than what a US 76mm weapon brought to the battlefield.

This would have been a possibility...

http://www.panzerbaer.de/workshop/llm_mod_35-c.htm
 

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Yes, but the newer posts are pathetic. There was a good thread regarding the JSII armor and a guy was measuring a specimen. To his credit, he was not a CM 'regular' (or irregular as I see them). I was surprised to see that the Soviets used hard durometer isolation mounts (rubber) under the mantlet.
That guy did a good job. I think he posted on the Archive site awhile back. I was trying to get someone to check out the JSII turret in a museum in Connecticut.
 
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