75-mm M3 v. Mk IV armor

[Jonathan Chin]

I am not very sure if this is the right forum. Mods, if inappropriate, please move it.

 

I am a fed up by wiki's refusal to change their class A article on how Panzer Mark IV was invulnerable to M3 fire to regular ranges. So I have a couple of rudimentry questions. Now the folowing is what my research indicates:

 

Panzer Mark IV H had 80mm of armor on mantlet that covers most of the turret front, superstructure front as well as brow. On the H model the 80mm mantlet was FH plate, the rest was RHA. Mk IV J changed the entire frontal armor to RHA to save manufacturing costs.

 

If my sources are right, then the American M72 one-piece AP round have more than enough penetration at least on paper to penetrate the 80mm armor of the ausf. H. But FH plate was designed specifically to shatter one-piece AP shots and I have read of the poor performance of American and Russian solid shots against FH armor.

 

The M61 APCBC on the other hand could penetrate 3-in. of FH plate at 1,000 yards. That should give it the ability to kill a Mark IV H at long range by mantlet hit. But hits elsewhere might not be effective. Against Mark IV J however it had insufficent performace to penetrate the RHA armor.

 

So, my question is, in ETO, what was the typical AP round loaded on a Sherman tank, the M61 or M72? And how successful was the FH was at shattering one-piece AP shots? This conerns me because if the M72 was reasonably effective, then a Sherman crew should load mostly M72s, because it could deal with all threats effectively. But if the FH plate was effective, then the Sherman crew would need to carry M61s to defeat the Mark IV H at the expense of greatly deduced performance against Mark IV Js.

 

What do you guys think? Was killing Mark IV mostly about trying hit it in the sweet spot with M61? Or just shooting M72 at it until the Mark IV was dead?

[Lieste]

I am not very sure if this is the right forum. Mods, if inappropriate, please move it.

 

I am a fed up by wiki's refusal to change their class A article on how Panzer Mark IV was invulnerable to M3 fire to regular ranges. So I have a couple of rudimentry questions. Now the folowing is what my research indicates:

 

Panzer Mark IV H had 80mm of armor on mantlet that covers most of the turret front, superstructure front as well as brow. On the H model the 80mm mantlet was FH plate, the rest was RHA. Mk IV J changed the entire frontal armor to RHA to save manufacturing costs.

 

If my sources are right, then the American M72 one-piece AP round have more than enough penetration at least on paper to penetrate the 80mm armor of the ausf. H. But FH plate was designed specifically to shatter one-piece AP shots and I have read of the poor performance of American and Russian solid shots against FH armor.

 

The M61 APCBC on the other hand could penetrate 3-in. of FH plate at 1,000 yards. That should give it the ability to kill a Mark IV H at long range by mantlet hit. But hits elsewhere might not be effective. Against Mark IV J however it had insufficent performace to penetrate the RHA armor.

 

So, my question is, in ETO, what was the typical AP round loaded on a Sherman tank, the M61 or M72? And how successful was the FH was at shattering one-piece AP shots? This conerns me because if the M72 was reasonably effective, then a Sherman crew should load mostly M72s, because it could deal with all threats effectively. But if the FH plate was effective, then the Sherman crew would need to carry M61s to defeat the Mark IV H at the expense of greatly deduced performance against Mark IV Js.

 

What do you guys think? Was killing Mark IV mostly about trying hit it in the sweet spot with M61? Or just shooting M72 at it until the Mark IV was dead?

 

Not sure about your question, but I was under the impression that MkIV J/H armour on the hull front was 80mm, but the turret was only armoured to roughly 50mm, due to space/balance considerations.

[Jonathan Chin]

Not sure about your question, but I was under the impression that MkIV J/H armour on the hull front was 80mm, but the turret was only armoured to roughly 50mm, due to space/balance considerations.

 

According to Osprey the H turret was protected by a rather large 80mm mantlet, IIRC. But Soviet reports did speak of Mark IV H with 50mm turret, so I am unsure about that myself. Could it be that they were fighting Mark IV Gs with bolt on 30mm plates?

[Lieste]

According to Osprey the H turret was protected by a rather large 80mm mantlet, IIRC. But Soviet reports did speak of Mark IV H with 50mm turret, so I am unsure about that myself. Could it be that they were fighting Mark IV Gs with bolt on 30mm plates?

 

Not a definitive source, but Guns V Armour gives the protection of PzIV turret at 50mm FHS at 10 deg, and the mantlet as 50mm FHS at 0 or 30 deg. Hull as 80mm (FHS for H, RHA for J) at 9 deg and 12 deg, with the glacis 20mm at 72deg and the nose as 30mm at 60 deg.

[Jonathan Chin]

I generaly trust that website since it cites its sources. Thanks. Now, I should ask else where what ammunition type was prefered.

[Lieste]

I generaly trust that website since it cites its sources. Thanks. Now, I should ask else where what ammunition type was prefered.

 

 

As you've just eliminated 37% of the armour thickness over half the target, the choice of ammunition may be moot

 

I would not expect a front turret hit to be very good for the MkIV, although it might survive if struck obliquely, or if hit on the hull front with the weaker ammunition types.

 

From the M2 gun, the quoted RHA penetration is over 50mm at 30deg to around 1000m for the M72, and to 1400m for the M61 - this might be significantly less if the FHS is good quality and thick enough to resist a 75mm impact - you would need to check combat reports or more in-depth testing to confirm though.

 

The M3, has equivalent figures of 1400m and 1800m. The same provisos apply.

 

 

Neither round fired from either gun should be expected to penetrate the hull front for a 30 degree impact.

Edited May 2, 2009 by Lieste

[bad-dice]

I generaly trust that website since it cites its sources. Thanks. Now, I should ask else where what ammunition type was prefered.

I had a read and was not impressed with it Jonathan.

 

Try this site it will give you all of the data your after.

 

Tanks & Vehicles Database

[Mobius]

According to Osprey the H turret was protected by a rather large 80mm mantlet, IIRC. But Soviet reports did speak of Mark IV H with 50mm turret, so I am unsure about that myself. Could it be that they were fighting Mark IV Gs with bolt on 30mm plates?

No.

The front turret was 50mm and the mantlet was 50mm and had some angle to it which might make it equivalent to 57mm.

The overall frontal area the turret was smallish.

As the US ammo was tested against either Midvale or Carnegie steel and the Germans used none of it I don't know how well the US 75mm fared vs the turret.

[Jonathan Chin]

bad-dice,

 

Thank you the useful database. What particular errors have you found? I used that website for awhile simply because he cited sources. In case of Panzer Mark IV ausf H though they agree with one another: 50mm mantlet/turret, 80mm hull. Jesus, one would have thought more than fifty years after the war, we would at least agreed on the front armor thickness of the most common type of German tanks huh?

 

 

Moebius,

 

Mr. Harry Yeides' Tank Killers says that in American tests the M3 penetrated three inches of face hardened armor at 1,000 yards. The book referenced was America's Arsenal or something like that. The test was should be a standard American test. If it is, this would give M61 about 88mm of penetration, probably enough for the brow armor of the Panzer Mark IV ausf. H. Given FH was in general viewed as an inferior to RHA to most kinetic penetrators, I am kind of guessing that the online theory, which says that the Germans used FH to shatter crude one-piece AP rounds used in Russian tanks, is correct. According to a History of the 3 AD, Gen. Maurice Rose made a report to the Army about German tank weapons and cited the FH armor was one advantage of the Germans. It most have done something right, then.

 

Does anyone here, btw, believe in the wiki theory that Pzkw IV ausf. H was invulernable to 75mm M3 at regular battle range? I am very puzzled by the author of the page, especially because he insists that this came from p. 219Jentz and Boyle's book Pzkw IV ausf G-J, published by Osprey, but the book was shown to have just 48 pages on both GoogleBook and Amazon. My own Osprey reference books on tanks are always 48 pages long. What's up with that?

[Lieste]

bad-dice,

 

Thank you the useful database. What particular errors have you found? I used that website for awhile simply because he cited sources. In case of Panzer Mark IV ausf H though they agree with one another: 50mm mantlet/turret, 80mm hull. Jesus, one would have thought more than fifty years after the war, we would at least agreed on the front armor thickness of the most common type of German tanks huh?

Moebius,

 

Mr. Harry Yeides' Tank Killers says that in American tests the M3 penetrated three inches of face hardened armor at 1,000 yards. The book referenced was America's Arsenal or something like that. The test was should be a standard American test. If it is, this would give M61 about 88mm of penetration, probably enough for the brow armor of the Panzer Mark IV ausf. H. Given FH was in general viewed as an inferior to RHA to most kinetic penetrators, I am kind of guessing that the online theory, which says that the Germans used FH to shatter crude one-piece AP rounds used in Russian tanks, is correct. According to a History of the 3 AD, Gen. Maurice Rose made a report to the Army about German tank weapons and cited the FH armor was one advantage of the Germans. It most have done something right, then.

 

Does anyone here, btw, believe in the wiki theory that Pzkw IV ausf. H was invulernable to 75mm M3 at regular battle range? I am very puzzled by the author of the page, especially because he insists that this came from p. 219Jentz and Boyle's book Pzkw IV ausf G-J, published by Osprey, but the book was shown to have just 48 pages on both GoogleBook and Amazon. My own Osprey reference books on tanks are always 48 pages long. What's up with that?

 

No such thing as invulnerability.... however the hull is strong enough to seem a tough proposition (same thickness as the Tiger 1 side/turret armour) - the turret is too weak for this to be an adequate protection from a close range threat.

 

So it has partial immunity over part of the front, and is easily penetrated over the other parts. Even then, there will be spots on the hull front where the armour is weaker than normal (vision slits, bow mg slot etc), and penetration is not a fixed, repeatable phenomenon. A relatively small proportion of rounds hitting the turret will fail even at short range, and a relatively small proportion of rounds striking the hull will penetrate, even at longer ranges.

[Mobius]

Mr. Harry Yeides' Tank Killers says that in American tests the M3 penetrated three inches of face hardened armor at 1,000 yards. The book referenced was America's Arsenal or something like that. The test was should be a standard American test. If it is, this would give M61 about 88mm of penetration, probably enough for the brow armor of the Panzer Mark IV ausf. H. Given FH was in general viewed as an inferior to RHA to most kinetic penetrators, I am kind of guessing that the online theory, which says that the Germans used FH to shatter crude one-piece AP rounds used in Russian tanks, is correct. According to a History of the 3 AD, Gen. Maurice Rose made a report to the Army about German tank weapons and cited the FH armor was one advantage of the Germans. It most have done something right, then.

According to the 1944 Ordnance catalog.

The M3 penetrates 2.9"@500yd 20° with the M61 APC. and 2.6"@ 1000yds.

vs FH it penetrates 3.4"@500yd 20° with the M61 APC. and 3.1"@ 1000yds.

 

Here is a field test you might find interesting.

http://wargaming.info/ww2/ustest1.htm

[bad-dice]

bad-dice,

Thank you the useful database. What particular errors have you found? I used that website for awhile simply because he cited sources. In case of Panzer Mark IV ausf H though they agree with one another: 50mm mantlet/turret, 80mm hull. Jesus, one would have thought more than fifty years after the war, we would at least agreed on the front armor thickness of the most common type of German tanks huh?

 

Jonathan, I could see nothing in error within the ‘nuts-n-bolts’ statements of the article. The areas I am not impressed with are the background statements used to put the nuts-n-bolts data into context. The one you have picked out is one of these.

 

Some other statements I thought gave wrong impressions were regarding North Africa where only combat against Matilda II’s is mentioned. In 1942 he says the PzIVF2 was the only German tank capable of defeating T34 and KV1.

 

It’s a shame because as far as I am able to tell the descriptions of the PzIV technical developments are fine. If you can separate these from the context statements the article is OK. As it stands though it’s a bit like a History Channel program.

Edited May 3, 2009 by bad-dice

[Jonathan Chin]

Thanks, gentlemen, for your generous contributions. It is strange that the Germans would chose to uparmor the hull front but neglects the turret. I would expect the turret to be the part more likely to be hit. 50mm is unnervingly thin.

[Lieste]

Thanks, gentlemen, for your generous contributions. It is strange that the Germans would chose to uparmor the hull front but neglects the turret. I would expect the turret to be the part more likely to be hit. 50mm is unnervingly thin.

 

I understood it to be a matter of necessity, rather than choice. The tank commander is on the recoil line, and that limits the position the gun can be in, still recoil safely and be loaded with single piece rounds. The original L24 had rather anaemic ammunition, and it was fairly short, so there was little problem with the space, but the more powerful L43/L48 required a longer recoil stroke and more space for loading. Mounting the gun very far forward, and increasing it's mass had unfavourable impact on the balance of the turret, and it is this that prevents further uparmouring.

 

By comparison, the PzIII got fairly thick front armour in its final versions IIRC.

[Paul Lakowski]

I understood it to be a matter of necessity, rather than choice. The tank commander is on the recoil line, and that limits the position the gun can be in, still recoil safely and be loaded with single piece rounds. The original L24 had rather anaemic ammunition, and it was fairly short, so there was little problem with the space, but the more powerful L43/L48 required a longer recoil stroke and more space for loading. Mounting the gun very far forward, and increasing it's mass had unfavourable impact on the balance of the turret, and it is this that prevents further uparmouring.

 

By comparison, the PzIII got fairly thick front armour in its final versions IIRC.

 

Sounds about right. The Panzer IV turret was already too heavy with the 75mm Lang, so their was not much option to put more armor on the front turret, except maybe for removing it from the allround protection. The surface area comparison should be 3-4:1, so -5mm allround could boost the frontal protection to ~ 70mm? But it also may have been that such a move would also make the tank too 'front heavy'?

 

Since the Panzer III turret had smaller turret ring it was also smaller internal volume leading to smaller over all mass. Thus it could afford to get more frontal protection, since it could not mount the heavier 75L48 gun due to the turret ring size.

Edited May 3, 2009 by Paul Lakowski

[bad-dice]

Sounds about right. The Panzer IV turret was already too heavy with the 75mm Lang, so their was not much option to put more armor on the front turret, except maybe for removing it from the allround protection. The surface area comparison should be 3-4:1, so -5mm allround could boost the frontal protection to ~ 70mm? But it also may have been that such a move would also make the tank too 'front heavy'?

 

Since the Panzer III turret had smaller turret ring it was also smaller internal volume leading to smaller over all mass. Thus it could afford to get more frontal protection, since it could not mount the heavier 75L48 gun due to the turret ring size.

 

I asked the question about 50mm turret armour a couple of years back, and these same reasoning was brought out.

Claus B/CBO(?) brought up the fact that theoretically the problems could all be fixed by new turret uprated suspension etc. But it was always intended to end production of the PzIV, so the upgrades required never went ahead.

[mkenny]

[Does anyone here, btw, believe in the wiki theory that Pzkw IV ausf. H was invulernable to 75mm M3 at regular battle range? I am very puzzled by the author of the page, especially because he insists that this came from p. 219Jentz and Boyle's book Pzkw IV ausf G-J, published by Osprey, but the book was shown to have just 48 pages on both GoogleBook and Amazon. My own Osprey reference books on tanks are always 48 pages long. What's up with that?

 

It is actualy pages 19/20. The sentence is :

 

"The 80 mm thick frontal armour of the Pz IV was capable of withstanding attack from AP shells fired by the Russian T34/76 and the American 75mm gun.

[Jonathan Chin]

Thanks. Mystery solved. Why would the editors of wiki insist that the Mk IV, with its massive but ill-armored turret, is invulnerable in frontal engagements, even though they apparently own all the sources that proves the otherwise, is beyond me.

[Jonathan Chin]

double post

Edited May 4, 2009 by Jonathan Chin

[Kip Swanson]

Thanks. Mystery solved. Why would the editors of wiki insist that the Mk IV, with its massive but ill-armored turret, is invulnerable in frontal engagements, even though they apparently own all the sources that proves the otherwise, is beyond me.

 

Wikipedia -- use with caution.

[Mobius]

Because they've perpetuated a misconstrued statement that makes it look like the IV has 80mm (or equivalent) on the full frontal arc instead of just the hull. The problem with many historical references is the constant habit of purely parroting sources without any sort of independent research or verification. Its not just wiki, publications do it all of the time too - ie Me-109 armament as the classic technical example.

Hey, wiki also thinks the Soviet ZiS-3 76.2mm gun is 51.6 calibers long.

[supertsar]

So, my question is, in ETO, what was the typical AP round loaded on a Sherman tank, the M61 or M72? And how successful was the FH was at shattering one-piece AP shots? This conerns me because if the M72 was reasonably effective, then a Sherman crew should load mostly M72s, because it could deal with all threats effectively. But if the FH plate was effective, then the Sherman crew would need to carry M61s to defeat the Mark IV H at the expense of greatly deduced performance against Mark IV Js.

 

What do you guys think? Was killing Mark IV mostly about trying hit it in the sweet spot with M61? Or just shooting M72 at it until the Mark IV was dead?

 

The M72 round was declared substitute standard before the invasion of North Africa (November 1942). TM9 1901 notes this was changed to limited standard by 1944. By mistake some M72 did end up in North Africa in November 1942 and it was loaded in M3 Lees (along with M61). The troopers complained and the commanding general made sure it didn't happen again. This I believe was in Armored Thunderbolt by Zaloga.

M72 was used for training. You couldn't find it in the ETO in 1944. There was never a shortage of M61 - not enough German armor around to cause a shortage.

[Kip Swanson]

The British routinely used M72 in Combat during their various North Africa Campaigns. Grants at Gazala and Grants and Shermans during the various Alamein Battles. I don’t recall if they were still using it by the time of the Tunisian battles or if M61 had begun to replace M72.

[Mk 1]

Odd thing is I don't recall ever reading a first hand account, American, British or even German, that asserts that Shermans were not able to handle Pzr IVs at normal combat ranges.

 

There are stacks of the first-hand accounts about Panthers and Tigers. There are reports from field units of all kinds of testing of weapons and gnashing of teeth over 76mm guns or 17pdrs or APDS or putting HVAP projectiles on 17pdr cartridges or whatever, all searching for ways to defeat Panthers and Tigers, and no where in any of it is there any assertion that the Pzr IV or Pzr III are a source of concern. Some worries about what might happen if the Germans up-armored with a 20mm armor plate spaced some distance from the main armor (which they didn't), but no assertion in any of it that a regular tanker in his Sherman could not effectively handle a Pzr IV frontally at normal combat ranges.

 

How is it possible that no one in the combat zone noticed that the most numerous German tank was highly resistant, or even impervious, to US tank gunfire?

 

-Mark 1

Edited May 29, 2009 by Mk 1

[ShotMagnet]

Fear o' the Panther/Tiger?

 

And maybe because they didn't recognize the enemy AFV for what it was until after they had sufficiently ventilated it?

 

Speaking to the fear aspect; for my money mashing a spider into dissociate proteins is about the right level of overkill.

 

One might assume the same for American/Allied tankers with regard to target ID and treating all such contacts as 'FUCK! A TIGER!'

 

Whether they really are Tigers (or Panthers) or not.

 

 

Shot