British 75mm MkV tank gun

[CharlesM]

I've done some checking, and what I said earlier about the cats is not quite right (see below). Face-hardened armour was used on the 4, 6 and 8-wheeled German armoured cars, i.e from SdKfz 221 through to 234 inclusive.

Pzkfw III Ausf G onwards and IV Ausf F1 onwards had face-hardened frontal armour, except for the glacis which was homogeneous, presumably because the slope was so shallow that the extra hardness was not needed, except for the glacis on the Pzkfw IV Ausf D, which had only this plate hardened, but throughout, rather than just face-hardened. PzKfw III Ausf G onwards and IV Ausf F1 onwards had face-hardened upper and lower hull sides, but not turret sides or on any rear armour plates. The last 50% of PzKfw IV Ausf J had only homogeneous plates.

For Panthers it is a bit more complicated, and made worse by the fact that the armour on many Panthers (about 50%) was of poor quality dut to bad heating and quenching processes. Bear in mind that all notionally on PzKfw IV and Panther were often actually 82-85mm thickness. The notional 60mm plates on the Panther nose were usually 65mm, later up to 75mm.

Panther Ausf D had glacis and nose armour face-hardened, aslo upper and lower hull sides. Nowhere else. Panther Ausf A had a face-hardened glacis (poor quality) and a face-hardened nose plate, and face-hardened upper and lower hull sides, but from 9/43 only homogeneous plate was used. From the sdummer of 1944 about half of the Panthers produced had flawed glacis armour. One other reason apart from poor heat treatment may have been the reliance on carbon as a hardener as non-ferrous metals like nickel and chrome dried up. The Panther Ausf G therefore had only homogeneous plate, and again with a glacis plate that often cracked under impact.

Tiger I armour was of better quality, as it was produced earlier in the war, and appears to have always been homogeneous. Tiger II armour was also only homogeneous, but of inferior quality for the reasons already given. Jagdpanther armour was softer that Panther armour, and so less prone to cracking.

Let me know if you want sources.

[chuckfourth]

I see, very interesting. Thanks very much for this detailed reply. If I might dig around a bit further?
Do you think it might be possible that the 250 and 251 half tracks had face hardened armour? after all the plate thicknesses were the same as the armoured cars. Also Im surprised the early panzer III's wernt face hardened, being the MBT and all.
Ive also heard mention that panzer 1 is face hardened and I would speculate the pz 2 may have been as well?
This site
http://ourworld.compuserve.com/homep...s/Specs-02.htm
disagrees slightly as it mentions that pz 4 had face
hardened side turret armour? (f1 onwards)
I would indeed be keen to have a look at the references as well if thats possible.

Thanks in advance Chuck.

[CharlesM]

I can't find annything that mentions face-hardened armour on halftracks.

As for PzKfw IVs, it seems to depend on sources.

My previous post about German tanks is from Lorrin Rexford Bird and Robert D. Livingstone, World War Two Ballistics: Armor and Gunnery, 2nd edition, Overmatch Press, Albany NT and Woodbridge Conn 2001. No ISBN is given.

No two sources seem to agree on the PzKfW IV,and Tom Jentz's Osprey New Vanguard # 39 on the PzKfw IV Ausf. G, H and J is rather vague when he describes the Ausf. G as having face-hardened 50mm frontal armour and 30mm side plates - implying that the turret sides were also FH plates. The earlier Osprey Vanguard # 18 by the late Bryan Perrett mentions FH armour only in the context of British examination of a captured Ausf. E. The applique armour over the hull MG mounting was FH, as were "the port armour covers". The 20 + 20 mm hull sides were not FH.

This lack of consistency is not surprising and not unique to German AFV construction - much would depend on the availability of FH plates during construction. Bear in mind that FH was an expensive exercise as a large number of plates were cracked and had to be discarded, and ultimately the game was not worth the candle, especially as plates became progressively thicker in the gun / armour race.

[cbo]

Pzkfw III Ausf G onwards and IV Ausf F1 onwards had face-hardened frontal armour, except for the glacis which was homogeneous, presumably because the slope was so shallow that the extra hardness was not needed, except for the glacis on the Pzkfw IV Ausf D, which had only this plate hardened, but throughout, rather than just face-hardened. PzKfw III Ausf G onwards and IV Ausf F1 onwards had face-hardened upper and lower hull sides, but not turret sides or on any rear armour plates. The last 50% of PzKfw IV Ausf J had only homogeneous plates.

According to Spielberger: "Begleitwagen Panzerkampfwagen IV", all the 30mm thick frontal armour plates on the Ausf. D were to be facehardened. That would be the front lower hull plate and the front upper hull plate as well as the front turret. Of the additional 30mm armour plate that were bolted on to the front of the Ausf. D in the summer of 1940 the first 100 sets were face-hardened, the reminder homogenous steel.
In the Ausf. E, all 30mm plates were to be facehardened while the thinner plates as well as the 50mm plates were homogenous. It appears that this also applied to the add-on 30mm plates on the upper hull front.
In the Ausf. F, the goal was to have most front and side plates facehardened, which, judging from the British reports used by Bird & Livingston, seems to have been carried out. This reference states that the turet sides were not face-hardened, while Spielbergers book seems to indicate that they were - even the turret hatches were to be face-hardened.
The Ausf. G was basically and Ausf. F with a different gun and it seems that it carried on with the same face-hardened plates. The additional 30mm plates on the hull front were face-hardened according to Bird & Livingston, Speilberger remains somewhat unclear on the matter
The Ausf. H started out as an odd mix, as the earliest vehicles had the same front armour configuration as the Ausf. G (50mm basis with 30mm add-on armour), then gradually started to get 80mm plate on the lower front hull, then the upper front hull. These 80mm plates appear to have been for the most part homogenous plates. Ausf. H production started in May 1943 and the decision to go with 80mm homogenous plates had been made even before that.
This would appear to have left the Ausf. H with 80mm upper and lower front hull homogenous armour, face-hardened side hull armour while the turret would have the front and mantlet face-hardened and possibly also the sides.
With regards to the Ausf. J, it was ordered in June 1944 that starting August 1944, all previosly face-hardened plates should be made in homogenous steel.

cbo

[Cross]

If the British 75mm Mk.V and US 75mm M3 were almost identical, and used the same ammo. Why does the US M3 have PEN 10 and the UK Mk.V only PEN 8 in the game?

In the case of the M72 ammo, according to an earlier post on this thread, the Brits even improved that round, giving it a higher penetration.

I looked at a couple of penetration sources, and they say there was virtually no difference between the M3 and Mk.V. In one case they gave the M3 a much poorer penetration than the Mk.V with APCBC M61 rounds, but I suspect that was an error of some sort.

I know the Mk.V did not have great AP ability, but it should probably be better than it is in SP, and surely should be no different from the M3?

Or am I missing something here?


Cross

[Mobhack]

Originally Posted by Cross

If the British 75mm Mk.V and US 75mm M3 were almost identical, and used the same ammo. Why does the US M3 have PEN 10 and the UK Mk.V only PEN 8 in the game?

In the case of the M72 ammo, according to an earlier post on this thread, the Brits even improved that round, giving it a higher penetration.

I looked at a couple of penetration sources, and they say there was virtually no difference between the M3 and Mk.V. In one case they gave the M3 a much poorer penetration than the Mk.V with APCBC M61 rounds, but I suspect that was an error of some sort.

I know the Mk.V did not have great AP ability, but it should probably be better than it is in SP, and surely should be no different from the M3?

Or am I missing something here?


Cross

If you think the UK gun should be equal to the US one, then please provide some data to support your case.

I think the AP data for that gun is just one of those things that have been in the game data since the SP1 days, and its never been challenged/evaluated.

My opinion is that since it is the same ammo from the same sized tube, you are probably quite correct.

Cheers
Andy

[Cross]

What I find interesting about the first source, is that they say:

It may be tempting to assume the performance of the British 75mm gun is the same as the USA 75mm Gun M3 as the two weapons used the same ammunition and had the same calibre; however it is a completely different gun and at the very least the difference in calibre length would mean a difference in muzzle velocity and therefore penetration.

But then they go on to give the Mark V a 2mm better penetration!



75mm Mark V and VA (L36.5)

APCBC M61 at 30deg (mv: 618 m/s)
457m : 68mm

75mm M3 and M6 (L40 and M6 L39)

APCBC M61 at 30deg (mv: 619 m/s)
457m : 66mm

914m: 60mm

AP M72 at 30deg (mv: 619 m/s)
457m : 76mm
914m: 63mm

Footnote:
1. Ordnance, QF, 75-mm Mk. V and Mk. VA. Source: Chamberlain, Peter and Ellis, Chris: British and American Tanks of World War II; Gudgin, Peter: Armoured Firepower and Churchill Tank - Vehicle History and Specification. This gun was a bored out 6-pounder chambered to use available 75mm ammunition from the USA. It may be tempting to assume the performance of the British 75mm gun is the same as the USA 75mm Gun M3 as the two weapons used the same ammunition and had the same calibre; however it is a completely different gun and at the very least the difference in calibre length would mean a difference in muzzle velocity and therefore penetration. None of the armour piercing projectiles had any explosive filler. The USA projectiles for the 75mm gun which were used by the British, such as the M61, had the HE filler removed when in British service.

http://www.friweb.hu/gva/weapons/british_guns5.html
http://www.friweb.hu/gva/weapons/usa_guns5.html
---

(All data is displayed in milimeters (mm) vs. RHA / FHA plate @ 30°)

75mm Mark V

APC M62 (mv: 618 m/s)
500: 67/65
1000: 52/49
1500: 40/37

75mm M3

APC M62 (mv: 588 m/s)
500: 64/75
1000: 57/68
1500: 51/61

APC M61 (mv: 617 m/s)
500: 69/67
1000: 61/58
1500: 53/49

AP M72 (mv: 619 m/s)
500: 73/58
1000: 59/45
1500: 47/34

http://www.tarrif.net/
---

75mm V and VA

yds
APC
500: 68
1000: 61
1500: 54

75mm M3

yds
APC
500: 70
1000: 59
1500: 55

75mm V and VA

yds
APCBC
500: 103
1000: 94
1500: 86

75mm M3

meters
APCBC
500: 75.3
1000: 62, 68.5
1500: 48, 55

75mm V and VA

meters
APCBC M61
500: 100
1000: 93
1500: 82

75mm M3

Meters
APCBC M61
500: 100
1000: 93
1500: 82

75mm V and VA

yds
AP M72
500: 76
1000: 63
1500: 51

yds
APC M61
500: 66
1000: 60
1500: 55

meters
APCBC
500: 69.5
1000: 63
1500: 57

75mm M3

Meters
APC M61
500: 70, 68
1000: 60, 59
1500: 55

Meters
AP
500: 76, 70
1000: 63
1500: 51

http://www.wwiivehicles.com/unitedki...ion-tables.asp
http://www.wwiivehicles.com/usa/guns/75-mm.asp

---

Bovington Museum, 1975
"Fire and Movement", RAC Tank Museum, Bovington, 1975, pages 22–25. "Penetration v. homogenous armour at 30º, at ranges in yards". The armour is machineable quality.

75mm Mk V

APC
500: 68
1000: 61
1500: 54

APCBC
500: 103
1000: 94
1500: 86

75mm M2 and M3

APC
500: 70
1000: 59
1500: 55

APCBC
500:
1000: 62
1500: 48

---

Chamberlain & Ellis, 1969
"British and American Tanks of World War II", Peter Chamberlain and Chris Ellis, A&AP, 1969, pages 202–207. Ranges in yards, armour type not specified, at 30º.

75mm Mk V, VA

500: 68

75mm M3

500: 70

75mm M2

500: 60


---

Ellis et al, 1962
"Victory in the West, Volume I: The Battle of Normandy", Maj. L F Ellis with Capt G R G Allen, Lt-Col A E Warhurst and ACM Sir James Robb, HMSO, 1962, page 549. "Penetration against homogenous armour plate at 30º angle of attack", ranges in yards.

75mm M3

APCBC
500: 74
1000: 68
1500: 60

perpetuates an error in Ellis by misidentifying the Sherman's 75mm gun as the British Mk V, when it is of course the US M3.

---

Ellis, 1993
"The World War II Databook", John Ellis, Aurum, 1993, page 304. Ranges in yards, armour type and slope not stated.

75mm M3

M61 APCBC
500: 66
1000: 61

---

Featherstone, 1973
"Tank Battles in Miniature: A wargamer's guide to the Western Desert Campaign 1940–1942", Donald Featherstone, Patrick Stevens Ltd, 1973, pages 141–143. "At 50º–90º angle-of-impact gun can penetrate maximum armour thickness of: (in millimetres)", ranges in yards, armour and ammunition types unspecified.

75mm M3

At 50 deg
600: 62
1000: 50

---

Gander & Chamberlain, 1977
Airfix Magazine guide 26, "American Tanks of World War 2", Terry Gander and Peter Chamberlain, Patrick Stevens Ltd, 1977.
Ranges in yards, ammunition type and armour type and slope unspecified.

75mm M3

500: 70

---


Grove, 1976
"World War II Tanks", Eric Grove, Orbis, 1976. Armour type unstated, conventional armour-piercing ammunition unless otherwise stated, ranges in yards.
At 30 deg

75mm M3

500: 70

---
Hunnicut, 1978
"Sherman, A History of the American Medium Tank", R. P. Hunnicutt, Presidio Press, 1978, pages 559–570. Ranges in yards; armour type (FH = Face-hardened, H = Homogenous) as shown at 30º.

75mm M3

APC (H)
500: 66
1000: 60
1500: 55

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WO 185/178, Tank armament versus armour.
This file is dated 1943.
"Perforation of armour in millimetres":

75mm M3

AP M72 (MQ armour at 30deg)
500: 73
1000: 64
1500: 55

APCBC M61 (MQ armour at 30deg)
500: 76
1000: 69
1500: 58

APCBC M61 (FH armour at 30deg)
500: 75
1000: 67
1500: 52

"Thickness of armour penetrated by 80% of projectiles striking the plate at an angle of 30º to the normal":
(MV 2050 fps)

APCBC M61 (MQ armour at 30deg)
500: 69
1000: 62
1500: 47

APCBC M61 (FH armour at 30deg)
500: 74
1000: 65
1500: 50

A memo from the Ministry of Supply dated 1st April 1943 gives the following figures for "Single homo plate penetration at 30º in mm.":

A memo from the Ministry of Supply dated 1st April 1943 gives the following figures for "Single homo plate penetration at 30º in mm.":

APCBC (MV 2030 fps)
500: 69.5
1000: 63
1500: 57

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WO 219/2806, Appendix G to SHAEF/16652/GCT/Arty
Dated 11 July 1944. "Perforation of homo at 30º Strike", ranges in yards.

US & Br 75mm

APCBC M61
600: 100
1000: 93
1600: 82

Comments and corrections
The high figures for the 75mm gun match those given for APCBC in the Bovington "Fire and Movement" booklet, but are much more generous than other sources. A memo in this document says there seems "little to choose" between the 75mm and 76mm.

---

WO 291/741, "Comparison of the performance of 75mm and 76mm tank gun ammunition."
"Thickness of homogenous armour plate penetrated at 30angle of attack by APCBC/HE shell." Ranges in yards.

75mm

APCBC
600: 68.5
1000: 63
1600: 55

Comments and corrections
Precision in fractional millimetres seems excessive, and suggests results by interpolation rather than measurement. This document also compares the HE performance of the two guns, concluding that in this respect the 75mm is noticeably superior. It also points out that inferior HE performance can be compensated for by using more of the less effective shell, whereas it is impossible to remedy a deficiency in penetrative performance.---

Zaloga & Sarson, 1993
"Sherman Medium Tank 1942-1945", Steve Zaloga and Peter Sarson, Osprey 1993, pages 10 and 14. Armour type and slope unspecified, ranges in yards.

75mm M3

APC M61
500: 68
1000: 60

---

I took all the cited penetration and recorded them on a spreadsheet for the type of ammo they listed and ranges 500,1000,1500:



I put the averages at the bottom (in bold).

Then I changed the results from mm to cm (at the very bottom).

Of the 16 results I have for both weapons, 8 were same, 5 were higher for the Mark V, and 3 were higher for the M3.

Not the most scientific study, but based on the data that's available it shows that the weapons were considered quite similar.

In the game, it could be that the Mk V is a bit underpowered and the M3 a bit overpowered.


Cross