M10's Against Panthers in Normandy

[rexford]

Jeff Duquette has posted a variety of reports from the 899th TD unit regarding their Normandy combat against Panther tanks (Yahoo! Tankers site). In fighting at 200 yards or less the only M10 penetrations of the Panther frontal armor took place against the bow machine gun ball, the lower front hull and ricochets off the mantlet bottom that went through the hull top.

The following analysis looks at some of the penetration-armor details and speculates that mantlet penetrations should have occurred but didn't (possible shatter gap failure due to overpenetration) and the Panthers had 50mm front lower hull armor.

The analysis also suggests that the Panther A's fired at during the U.S. August 1944 Isigny tests had 67mm front lower hull armor, which exceeds the design spec of 60mm by 12%.

A comparison of penetration figures for U.S. 75mm and 76mm APCBC is also made using TM9-1907 and British test results, showing that wide variations in quality were possible. U.S. quality control tests with those two rounds showed that the best and worst ammo varied by 20% in velocity needed to defeat the given thickness, which translates into the best doing 15% more than average at a given velocity, and the worst falling under average by 14%.

The above is a summary and the details follow:

===============================================

A few issues related to the subject combat:

1.

If 76mm rounds from the M10 were hitting the mantlet bottom and front lower hull, it seems reasonable to assume some hits landed on the mantlet center area. Given a range under 200 yards, 76mm APCBC would penetrate around 124mm vertical while the Panther mantlet would resist like about 95mm rolled plus angle effects.

So, if 76mm APCBC lands near the mantlet apex how come no reported penetrations of the mantlet?

One way of explaining away the absence of mantlet penetrations is possible shatter gap, where the 76mm APCBC overpenetrated the mantlet armor and broke up due to the immense inertial forces.

During the U.S. Navy tests with 76mm APCBC against 3.82" inch armor (97mm) at 20 degrees, hits at 2526 fps shattered and hits at 2573 fps penetrated. Against the same approximate armor thickness at 30 degrees, hits near the M10 muzzle velocity shattered and failed while hits at 2495 fps penetrated (analysis limited to Brinell Hardness under 340 to eliminate high hardness anomalies).

2.

The 76mm penetrations of the Panther front lower hull by M10's may have taken place against 50mm plates.

3" APCBC penetrates 124mm vertical at 100m (TM9-1907 data), and 60mm at 53 and 55 degrees from vertical resists like 131mm and 141mm vertical equivalent (53 degrees considers ground tile favoring M10 hit).

If the Panthers were carrying 50mm front lower hull armor, the resistance at 53 and 55 degrees impact would equal 104mm and 112mm and M10 hits would easily penetrate at 150 meters.

At Isigny, the front lower hull armor on a Panther was measured at 66.7mm (more than 10% above the spec), and 76mm APCBC failed to penetrate the Panther nose at 400 yards.

Also at Isigny, 76mm HVAP failed to penetrate the Panther nose on one hit at 600 yards and succeeded on one hit out of two at 400 yards,

The 76mm HVAP penetration at 400 and 600 yards is 218mm and 204mm vertical, whereas the vertical resistance of 66.7mm at 53 degrees is 207mm (ground tilt at Isigny favors projectiles by two degrees). 60mm at 53 degrees resists like 186mm vertical.

The Isigny trials suggest that the front nose armor on the test Panthers was around 67mm based on comparison to 76mm HVAP hit results and penetration.

I'am assuming that 76mm ammo was not fired against any Panther G's at Isigny, and that Panther G's were involved in the fighting at Le Desert.

3.

British trials with U.S. 75mm and 76mm APCBC resulted in significantly higher figures than TM9-1907 at close range, an issue that is addressed on page 57 of our book. While TM9-1907 has vertical armor penetration figures of 90mm and 127mm for 75mm and 76mm APCBC at 0 yards, WO 291/741 has 101mm and 140mm (see John Salt's penetration page at British Wargamers for complete details).

We figured that the Brits used best quality American ammo in their trials, and our book and calculations use more conservative (lower) penetration data for American and British ammo.

If the British figures for 75mm and 76mm APCBC, the results would not be consistent with reported firing test and combat results against Panther and Tiger tanks. Which is why we chose the lower penetration numbers, they look better after comparison to attack on actual German armor.

Lorrin

[JasonC]

So because hyper-velocity rounds sometimes glance off 55 degree angle plates (angle effect in reality is a function of engagement velocity, and HVAP doesn't help against highly angled plates), the lower hull is supposed to be invulnerable when anywhere near spec thickness. And because a few dead Panthers don't have holes through their mantlets (because they were killed elsewhere) the mantlet is supposed to be invulnerable (presumably to anything but tungsten). The glacis already was. So the Panther is supposed to be an invulnerable ubertank from the front vs. US 76mm.

Despite the fact that in reality, as opposed to your more and more tendentious, German bias minutae twisting, Panthers on the attack in the west fared remarkably poorly and were routinely trashed by M-10s and M-18s. As Panzer Lehr's July counterattack, Mortain, and the smoking ruins of the Panzer brigades in August and September make abundantly clear.

We've got direct AARs of M-10s outscoring Panthers in hedgerow country, with German panzer generals lamenting how useless it was attacking in such terrain. We've got direct AARs of M-18s outscoring Panthers at close range in Lorraine, when the fog meant to keep the Jabos away also meant no long range against the TDs. Your own favorite tests show the mantlet regularly penetrated by 76mm plain AP at close enough range.

The truth of the matter is the only plate on the Panther immune to US 76mm was the glacis. The rest of the front require close range with plain AP. This was enough to make the Panther marginal on the attack in the terrain and environmental conditions regularly encountered in the west, not much better than Pz IVs.

To exploit its strengths, it needed to defend, thus choosing its own ground to fight at range showing only its frontal facing. When it had to advance, it either showed its sides or moved directly on enemy positions - which the enemy picked, thus giving him the choice of opening range. It did not help that German operational doctrine on the use of armor was overly offensive. Or that in the west such attacks mostly had to be conducted in poor weather, covered terrain, or both - to avoid Allied air.

I used to respect the extent of your learning on armor grog matters, Rexford. But of late, you have been pushing your German bias with such strained arguments it has gotten to the point where I don't believe a word you say. One man's opinion.

[ January 05, 2004, 08:33 AM: Message edited by: JasonC ]

[Jack Carr]

Originally posted by JasonC:

So because hyper-velocity rounds sometimes glance off 55 degree angle plates (angle effect in reality is a function of engagement velocity, and HVAP doesn't help against highly angled plates), the lower hull is supposed to be invulnerable when anywhere near spec thickness. And because a few dead Panthers don't have holes through their mantlets (because they were killed elsewhere) the mantlet is supposed to be invulnerable (presumably to anything but tungsten). The glacis already was. So the Panther is supposed to be an invulnerable ubertank from the front vs. US 76mm.

Despite the fact that in reality, as opposed to your more and more tendentious, German bias minutae twisting, Panthers on the attack in the west fared remarkably poorly and were routinely trashed by M-10s and M-18s. As Panzer Lehr's July counterattack, Mortain, and the smoking ruins of the Panzer brigades in August and September make abundantly clear.

We've got direct AARs of M-10s outscoring Panthers in hedgerow country, with German panzer generals lamenting how useless it was attacking in such terrain. We've got direct AARs of M-18s outscoring Panthers at close range in Lorraine, when the fog meant to keep the Jabos away also meant no long range against the TDs. Your own favorite tests show the mantlet regularly penetrated by 76mm plain AP at close enough range.

The truth of the matter is the only plate on the Panther immune to US 76mm was the glacis. The rest of the front require close range with plain AP. This was enough to make the Panther marginal on the attack in the terrain and environmental conditions regularly encountered in the west, not much better than Pz IVs.

To exploit its strengths, it needed to defend, thus choosing its own ground to fight at range showing only its frontal facing. When it had to advance, it either showed its sides or moved directly on enemy positions - which the enemy picked, thus giving him the choice of opening range. It did not help that German operational doctrine on the use of armor was overly offensive. Or that in the west such attacks mostly had to be conducted in poor weather, covered terrain, or both - to avoid Allied air.

I used to respect the extent of your learning on armor grog matters, Rexford. But of late, you have been pushing your German bias with such strained arguments it has gotten to the point where I don't believe a word you say. One man's opinion.

Amazing info. Panther not much better than PZIV at the ranges and visual limitations really says alot. It certainly explains why the German big cats were ultimately bested. Besides having fewer numbers the combat apparently took place at ranges which favored the quicker vehicle.

[JasonC]

Quicker vehicle - to fire, more than road speed movement. It was the sighting differential and resulting first shot that usually decided the really short range shoot-outs. On the attack, the Germans were often inside the US defensive zone, and often stripped of their infantry already. They were typically buttoned. The open TDs found it easier to see them, and probably to hear them too.

Lehr's counterattack in mid July -

"in position about 300 yards east of le Desert on the road to la Perrine, attacked three tanks which had penetrated the American lines for 500 yards. During a fight in which one American TD was knocked out, one of the enemy tanks was destroyed and the other two were forced to withdraw after being set afire.

To the west of le Desert, approximately ten German tanks drove north on the unimproved road leading from the le Hommet-d'Arthenay crossroads to la Charlemenerie and succeeded in reaching a point just south of la Scellerie. Here the column was stopped when the 3d Platoon, Company A destroyed the leading German tank after losing one of its own M-10's. To deal with the German threat in this area, the Company A commander reorganized his tank destroyers and requested a company of infantry as reinforcements. While awaiting the arrival of these troops, the TD's spotted three Mark V tanks on the road west of la Scellerie and opened fire, destroying with 12 rounds the tanks and one half-track.

Later in the morning, Company C, 899th Tank Destroyer Battalion, holding positions near la Charlemenerie, knocked out its first German tank of the campaign. A well-camouflaged Mark V, carrying several soldiers and accompanied by others on foot, rounded the west corner of the crossroads below la Charlemenerie in front of an American tank destroyer. The M-10 opened fire and with two shots destroyed the German tank, killing and wounding several crew members and scattering the rest.

Another Panther thrust in the early afternoon toward la Charlemenerie, near the la Caplainerie road junction, was stopped by two of Company C's tank destroyers with the aid of Company F, 32d Armored Regiment (Combat Command A). The Company F tanks were located in orchards on either side of the road waiting to take part in a 47th Infantry mission, while the two M-10's were holding positions on the road about 200 yards from the American armor. As the Mark V's appeared, Company F opened fire with HE at a range of 400 yards. The Panthers continued to roll, however, and the leading tank broke through to fight a duel with an M-10 at a range of 120 yards. The Mark V was damaged by TD fire, but it returned a shot, hitting the TD and wounding or killing three members of the crew. The other M-10 then opened fire, finishing the Panther with two shots. Then, spotting another Mark V, the TD fired ten rounds into the suspension system of the Panther, which sideslipped helplessly against the bank on the east side of the road and hung there in a tangle of matted hedgerow and churned mud. The crews, who had left their tanks when they were hit, were tracked down by infantry and captured in a farmhouse in the vicinity.

The slaughter of the German armor continued. As the 1st Battalion, 47th Infantry moved down the road west of la Charlemenerie to contact the 3d Battalion, the first two M-10's in the column spotted two Panther tanks approaching from a lightly wooded area to the left front. Before these tanks could get into action, the TD's opened fire with their 3-inch guns at a range of 170 yards, knocking out both Panthers. A few moments later a third Mark V was discovered on a farm road to the east. Both M-10's fired on it, and ten minutes later this third tank was found pitched inert against a hedgerow. None of the enemy tanks had been able to fire on the 1st Battalion before being hit.

In sum the enemy armor had floundered helplessly after its breakthrough."

That TD unit killed 12 Panthers and 1 Pz IV for a loss of 3 M-10s. As the narrative shows, the range was typically 120-200 yards, at most 400 on first sighting. The Germans often did not get a single shot off. Sometimes they survived the first hits and killed 1 M-10, before losing the engagement.

The best the Panthers managed in the Arracourt fighting was an even exchange with M-18s they ran onto in fog. In other places in August and September, fresh brigades were cut in half inside 48 hours, taking fewer plain Shermans with them than they lost Panthers - let alone upgunned TDs.

On defense with long open lanes of fire the Panther could be a very effective tank killer. But charging into the enemy defense both blinded them, and exposed their thin sides if the ground was open. While Allied TDs (and for the Brits, Fireflies) could stop pure frontal moves where the flanks were covered, in thick terrain, from positions with short LOS lines.

If they had been nearly invulnerable from the front even at close range they would have been terrors in the hedgerows. They weren't. The head of Lehr talks about what a waste it was to attack with them in that terrain.

"Bayerlein attributed the result of the day to the exhausted condition of his men when they entered battle, and to the difficulty of operating Mark V tanks in the hedgerows. He declared that his armor had to fight at maximum ranges of 200 yards because hedges concealed everything farther away. He could not use the Mark V's for cross-country movement."

[ January 05, 2004, 11:13 AM: Message edited by: JasonC ]

[flamingknives]

Jason, I fail to see how Lorrin is wrong ad you are right. His post references AARs, technical manuals and War Office documents, and make little supposition without backing it up with numbers.

On the other hand, your counter-evidence provides no direct contradiction, Panthers are reportedly knocked out, but the location of the hit is not given, only the approximate engagement direction.

For starters, if someone with slope effect figures could give an idea of the angle at which the 3" gun will start going through the side armour of the Panther, that would be useful.

[Mr. Tittles]

A concievable effect about the Panther mantlet is its shape. When viewed from the side, its a semi-circular shape. This shape may actually give strength to the 'vertical' portion of the semi-circle. The effect is similar to the strength a bridge has. Its strength comes from the arch shape. So the panther mantlet armor, even at its least angle (near the MG and sight openings), is stronger than a plate of vertical armor of the same thickness. This effect would also depend on the AP penetrator diameter, smaller (APDS) being better for the penetrator.

The lower part of the semi-circle led to the infamous downward deflections. Penetrations of this same lower area (shots going through), will actually bounce upwards into the roof of the turret. Likewise, penetrations through the top part of the mantlet would bounce downward into the turret basket area.

All in all, the panther mantlet could have been better (and was improved) but was probably a compromise to mass production.

[ January 05, 2004, 12:43 PM: Message edited by: Mr. Tittles ]

[Mr. Tittles]

7) 3-inch Gun, M5, mounted on Motor Carriage, M10

a) APC M62, w/BDF M66A1 will not penetrate front glacis slope plate at 200 yards. Will penetrate gun mantlet at 200 yards and penetrate sides and rear of the 'Panther' Tank up to 1500 yards.

http://www.geocities.com/mycenius/

[Crank_GS]

Hi JasonC,

Good stuff there. Where did you get it? If it is from a book, I would love to read the whole thing.

Thanks.

PS> Get your car shoveled out? I'm in Chicago, too.

[rune]

Hijacking thread for a moment.

Crank, next time we have a get together in Chicago, you got to come. You are more then welcome to show up.

Rune

[Crank_GS]

Get-togethers? In Chicago? Really. That is cool. Are they posted here-abouts? Sounds like some fun!

Where do they usually happen?

[JasonC]

Rexford is trying to say that since the Panthers with holes in them examined by the 899 didn't include holes through the mantlet, the 76mm couldn't get through the mantlet.

"speculates that mantlet penetrations should have occurred but didn't (possible shatter gap failure due to overpenetration)"

The engagements are the ones described in the above history. Notice in those histories, if the M-10s hadn't killed 'em fast they would have died themselves. They killed 'em fast. They didn't need to accumulate a whole bunch of hits. Not every hit killed, but usually 2 sufficed.

Rexford has no reason at all to believe the 76mm *couldn't* get through the mantlet. He just has a handful of dead tanks whose holes from 76mm are elsewhere. His own cited US tests show the 76mm going through the mantlet at 200 yards. But he spins holes elsewhere, as "can't be penetrated through the mantlet", and assigns shatter gap as the supposed reason. When at 200m and under, the 76mm is overpenetrating by more than enough to defeat shatter. (If there were no gap, it'd kill them out to more like 1000 yards through the turret front).

Then, the holes in the handful of 899 kills he is talking about do include holes in the lower front hull. But he doesn't want Panthers to be penetrable through the lower front hull by US 76mm. Even though the tanks so killed are right in front of him, and he is cited them as evidence that the kills didn't happen through the mantlet. His explanation? "the Panthers had 50mm front lower hull armor".

These are Panzer Lehr vehicles. The pick of the German army. They were killed by US 76mm firing plain AP at ranges under 200 yards, from the front. But Rexford wants to just wave his hand, and make them as thin as Pz III Js. Without the slightest evidence from the actual vehicles.

What is his evidence for this entirely fanciful assertion? Why, the same tests that show the mantlet was penetrable at 200m. Because in them, the lower front hull was - oops, also penetrated. But not always. Some HVAP deflected instead. Since this is a 55 degree angle plate, this is hardly earth-shattering.

Then he says these plates the HVAP was deflected from - occasionally - were 7mm thicker than spec. And the angle was 2 degrees less than 55. What are these doing here? They are getting him an implied angle coefficient sufficient to make the built to spec Panther front hull look invulnerable to the plain AP 76. Even though the HVAP engagement and the AP engagement are at two difference velocities, and thus ought to have two different angle coefficients.

Instead, we are supposed to think HVAP is "better" than AP, by a lot, yet occasionally ricochets. Ergo the "worse" plain AP supposedly must only penetrate a much thinner plate. This twisted reasoning then faces the stone cold dead 76mm killed through the front hull Lehr Panthers, and - waves their thickness down to 50mm from 60mm. Sure, M-10s sometimes killed Panthers - but only 'flicted Panthers from the cancer ward with weak bones.

The entire thing is horsefeathers. The occasional HVAP failures against the lower hull are a direct consequences of HVAP vs. very high angle not always helping. The absence of mantlet kills in the Normandy handful is not evidence of an invulnerable mantlet, only that that particular handful of kills were killed through other plates first. Proof the mantlet is not invulnerable at 200m is right there in his own cited test.

Instead we are supposed to believe this lot was 10% thicker and that lot was 15% thinner and none of it was shot to shot variation, and to conclude (1) 76mm couldn't penetrate the lower front hull - when it did, in the very dead tanks in Normandy he is citing, and (2) 76mm couldn't penetrate the mantlet at 200m - when it did, in the very US test firings he is citing. He has direct evidence both plates were vulnerable, and wants to cite that direct evidence as supposedly "speculatively" "suggesting" the exact opposite.

[ January 05, 2004, 04:05 PM: Message edited by: JasonC ]

[flamingknives]

What I see is that there are two sets of figures for US AP ammunition - the British and the American.

Lorrin appears to be comparing both against actual firing results vs. Panthers, coming to the conclusion that the American numbers compare more closely to results in the field.

Differences from these figures at the firing tests at Isigny are accounted for by a non-standard lower hull. Even using the WO figures the numbers are marginal (140 vs. 141)

[Mr. Tittles]

web page

Click on small pic for 4 view of Panther

The front on image shows the Panther A from onwar.com.

The lower hull between the tracks is not a large target. It is not only hard to hit because of its size, but also because of its proximity to the ground. Tests cite this as a factor when trying to score a hit. A chance to hit this area would be about the same as hitting one of the tracks. Also, at close range on even terrain, a firer would be firing downward at this area making teh angle steeper. behind this area is the transmission and final drive components. not ammo. In hedgerow terrain, a panther behind a hedgerow would have this area protected.

The turret front (small triangular areas to the right and left side of turret) were only 110 mm and nearly vertical. This is more of a vulnerable area than the mantlet is.

The Glacis protects roughly half the front of the tank.

[ January 05, 2004, 04:52 PM: Message edited by: Mr. Tittles ]

[Mr. Tittles]

The tables extracted from a WaPruef 1 report dated 5 October 1944

http://www.geocities.com/desertfox1891/pzpanther/pzpanther-Charakteristics.html

The tables here show that the panther mantlet could be penetrated by the US 76mm gun at short range (100 meters) and the turret front (small area not protected by the mantlet) at 700 meters. This assumes a side angle.

The report claims that the US 76mm is more powerful than the Russian 85mm.

Using the Panther offesively or defensively in Hedgerows is just plain stupid. The weakest part, the turret, would naturally be seen and targeted.

[ January 05, 2004, 05:21 PM: Message edited by: Mr. Tittles ]

[dugfromthearth]

this reminds me of discussions on the World War II Online forum awhile back (I haven't played it, just looked into it).

One side was complaining that their tanks were supposed to be heavily armored, nigh invulnerable except for one weak spot - and that the kept getting hit and killed with the first shot to the weak spot.

The other side replied of course. They knew they had to hit that to kill the tank so they always aimed for it. It wasn't random chance or coincidence. It was deliberate enemy action.

If at 100m the TD can aim at a near invulnerable section, a semi-vulnerable section, or a vulnerable section, of course you would expect them to aim at the vulnerable section. So in actual results you would expect few shots at the semi-vulnerable area and almost no successful hits.

[Mr. Tittles]

In CM, the distribution of hits is not representative of the differences in vehicle layouts. So the Panther 'turret-front' 110 mm near vertical section, while being a very small area, might get a disproportianate number of hits.

In reality, the Germans had SOPs about engaging enemy vehicles. I believe they would stand off 600 meters in the case of the Panther. Battle in bocage did not allow such SOPs.

German tanks should have let infantry lead in such conditions. The Panthers would have no business carrying on an attack once its infantry was stripped.

[Mr. Tittles]

RECORD OF COMPARATIVE FIRING TEST

Shoeburyness - 23 May 1944

Rolled Homo @ 30º ; Service Velocity Ammunition

ROUND AMMUNITION*** RANGE ARMOUR

THICKNESS BDF

FUNCTIONING RESULTS**

PHASE I

1 90mm Shell, APC M82 800 yds 120mm yes PP - Depth 3", Bulge 3/8"

2 17pdr APCBC 800 yds 120mm - PTP

3 & 4* 90mm Shell, APC M82 400 yds 120mm yes PP - Depth 4", Bulge 1½"

5 76mm Shell, APC M62 400 yds 120mm no PP - Depth 21/8", Bulge 1/8"

6 90mm Shell, APC M82 100 yds 120mm yes PP - Depth 4", Bulge ¾"

7 76mm Shell, APC M62 100 yds 120mm no PP - Depth 2¼", Bulge 1/8"

This test shows PP (partial penetration) results. This is for 120mm sloped at 30 degrees from the certical.

[rexford]

JasonC,

I was suggesting that the absence of mantlet penetrations could have been due to shatter gap, not trying to make an ironclad case.

You also missed the point regarding Panther differences in lower front hull armor thickness. Penetration probability bears out my conclusions, all the words you threw at the issue show nothing.

Lorrin

[ January 06, 2004, 11:42 PM: Message edited by: rexford ]

[JasonC]

Rexford, you have dead Panthers killed by US 76mm through the mantlet at 200 yards and you have dead Panthers killed by US 76mm through the lower front hull at 200 yards. Do you conclude that Panthers can be killed through either plate by the US 76mm at 200 yards?

No. You want to conclude the exact opposite, killable through neither. You want as many varities of Panther as there are incidents you need to spin. You multiply entirely hypothetically guesses purely to deny the evidence right in front of you.

Why? Because you are biased, that is why. No other reason. You simply *want* unkillable Panthers. You don't give a damn that the actual ones were actually killed by that gun through both of those plates.

You will spin minutae and invent non-existent distinctions and pure guesswork endlessly, if they move the outcome in one direction. You aren't interested in the plainest reasoning that might move them in the other direction. You don't want a tactical simulation that gives realistic outcomes, you want a fantasy in which tanks you've decided you like are invincible.

You got away with some of this BS in CMBB, weren't called on it, and so you keep pushing. You aren't fooling me. You are fooling yourself.

[flamingknives]

Originally posted by JasonC:

Rexford, you have dead Panthers killed by US 76mm through the mantlet at 200 yards and you have dead Panthers killed by US 76mm through the lower front hull at 200 yards.

I shall step in again for the side of comprehension. In his original post, rexford references an AAR that breaks down hit locations on panther kills. There are none to the front mantlet, where there ought to be, given the thickness and penetration figures.

The penetration figure don't support the 3" gun being able to penetrate the lower front hull, when this in fact occured.

[rexford]

JasonC,

You completely missed the points, as often happens.

There were two official front lower hull thicknesses, 60mm on Panther D and A and 50mm on later Panther G, according to a variety of materials. I'am not trying to make up anything new, just stating where firing tests and combat results support 60mm+ or 50mm front lower hull.

U.S. measurements show 60mm design spec front lower hull measured 67mm, and firing tests with HVAP support that thickness when penetration probability is used to analyze the results. Please provide your mathematical analysis if you can show that my conclusions are erroneous.

I was speculating that some hits on the Panther mantlet by 899th TD M10's at Le Desert may have failed due to shatter gap, which requires a certain velocity range and certain impact angle range.

You missed the fact that the July 1944 tests showing a 200 yard penetration range for 76mm APCBC against Panther mantlet greatly underestimate the range where 76mm APCBC penetration equals the mantlet thickness. 76mm APCBC penetrates 100mm at 1250m, and even further when cast armor deficiency is considered.

Why does 76mm APCBC only penetrate the 100mm Panther mantlet at 200 yards, or not at all, in France during combat or trials?

In other U.S. tests against Panther, 3" M79 AP shattered against the center area of the Panther mantlet at close range, which strongly suggests shatter gap failure.

You seem to always interpret things so you can argue with me.

Lorrin

[ January 07, 2004, 07:53 AM: Message edited by: rexford ]

[Mr. Tittles]

Originally posted by dugfromthearth:

If at 100m the TD can aim at a near invulnerable section, a semi-vulnerable section, or a vulnerable section, of course you would expect them to aim at the vulnerable section. So in actual results you would expect few shots at the semi-vulnerable area and almost no successful hits.

This implys they know the vulnerable spot. After field test shoots, these spots could be detected.

But some spots are small enough that hitting them at 100 meters is not as easy as you think. The gunners sight is offset from the parallel barrel. Hitting something like a track (from the front), is entirely possible since the track width is large enough compared to the offset. Hitting a bow MG is not that easy.

The Panther mantlet-deflection shot is a small region. If you inspect the Panther G upgrade to the mantlet, it only covers the lower part but not up to the apex. The Germans probably did tests and resolved the improvement area. Most shoots uncovered the fact that the upper hull area was almost invulnerable and tracks and turret hits were probably SOP (as well as using smoke and reverse).

At 100m, the firing of the gun, flight of the shell and strike happen fairly quickly (about 1/8th of a second). Juddging where a strike is located would be difficult at best. Firing a coax could help under this circumstance. The continuous stream of tracers and sparks from the bullet strikes would correlate with the strike of the main gun round (differences in velocity would be negligible).

I don't believe the mantlet was as vulnerable as games make it out to be. As I said before, The 'vertical' portion of the curved mantlet represents a very small area of '120mm' cast armor. The deflection area is small also and the 110mm 'turret-front' areas are also small.

Other vulnerable areas are the commanders copula, the bow MG.

[Mr. Tittles]

Originally posted by rexford:

I was speculating that some hits on the Panther mantlet by 899th TD M10's at Le Desert may have failed due to shatter gap, which requires a certain velocity range and certain impact angle range.

You missed the fact that the July 1944 tests showing a 200 yard penetration range for 76mm APCBC against Panther mantlet greatly underestimate the range where 76mm APCBC penetration equals the mantlet thickness. 76mm APCBC penetrates 100mm at 1250m, and even further when cast armor deficiency is considered.

Why does 76mm APCBC only penetrate the 100mm Panther mantlet at 200 yards, or not at all, in France during combat or trials?

In other U.S. tests against Panther, 3" M79 AP shattered against the center area of the Panther mantlet at close range, which strongly suggests shatter gap failure.

Lorrin

http://www.geocities.com/desertfox1891/pzpanther/pzpanther-Charakteristics.html

I believe this data also shows that the mantlet is much stronger than the turret front.

If you look at the ranges where the turret front and mantlet are vulnerable, there is quite a discrepency. That is, there must be a reason for its strength. The shatter gap theory may explain some instances but I suggest that the curved nature of teh cast mantlet actually increases its strength beyond what a normal flat piece of cast armor would have.

As a AP shell enters the mantlet front, it starts penetrating normally. Once inside, it has to push through and displace material. As it enters into the mantlet, there is an increased 'side-effect' because of the shape of the material. Its the same effect that makes bridges or egg shells strong from attack against the curved area.

I believe this effect offsets any degrading effect that cast armor usually has.

[rexford]

German data and production drawings on the Panther mantlet show a maximum thickness of 100mm.

The armor is cast so will be inferior to rolled homogeneous armor.

Theories aside, British firing tests with a variety of weapons and ammunition show that the 100mm Panther mantlet casting resists penetration like a lower thickness of rolled homogeneous armor when it is hit around the apex (center area).

Web site presentations of penetration ranges are often based on paper comparisons of penetration data to armor resistance at some unstated impact angle, and who knows what data was used. Actual firing tests against the Panther mantlet show that it was inferior to 100mm rolled homogeneous armor around the center point.

The American firing tests showed Panther mantlet penetrations at 200 yards max range by 76mm APCBC, where ammo penetrates about 123mm vertical. Hits at 15 degrees impact angle would be resisted by about 101mm vertical resistance, so why the 200 yard max range?

My theory is that shatter gap may have played a part, since the ammo failed in U.S. Navy tests when it hit 3.82" plate at 20 degrees and a velocity pretty close to muzzle velocity even though it should have easily penetrated.

Lorrin

[Mr. Tittles]

76mm Shell, APC M62 500 yds 100mm no PTP

This data is from shooting at a test plate 100mm thick 30 degree slope RHA.

The US 76mm achieved a complete penetration at 500 yards.

Now, you are saying the Panther mantlet is 100mm cast armor. If hit at the apex; why does it have to be 200 meters? If it penetrates (completely) at 500 yards a plate of angled/better quality, why is it having such a problem with cast armor and needs a shorter range? I am assuming that the shoots started at a certain range and as no penetrations occurred, they moved the firing weapon closer.

Is there other data that supports shatter gap against cast armor for other guns/targets?

There ARE failures in these tests from the base HE going off prematurely by the way.

I think a better question is why is penetration of the cast mantlet such a problem?

The only shatter data you show is point blank range? How is that a 'gap'?

[ January 08, 2004, 10:18 AM: Message edited by: Mr. Tittles ]