Looking to discuss 2pdr effectiveness in RL and CMAK

[flamingknives]

Good first post BillyBob.

A 6pdr would definately make it uncomfortable in a PzIII

[The Green Rascal]

LOL thanks Billybob, nice typo from me. They were of course Cruiser IIIs not Crusader IIIs

[The Green Rascal]

LOL thanks Billybob, nice typo from me. They were of course Cruiser IIIs not Crusader IIIs

[DevilDog]

I read something interesting this morning in a non-grog book that I hadn't heard before. Don't know if is accurate or not. The book claimed that for over a year, possibly up to two years the Brits didn't know the Germans had face hardened armor which caused Brit AP shot to shatter. Inability to spot the impacting AP rounds (I don't remember the reason why) lead the Brits to mistakenly think they simply had accuracy problems and they worked on improving marksmanship, instead of realizing there was a serious technology gap.

Is it possible that the discrepancy between CMAK and RL reports is the result of projectile shatter? I know the Allied shells had serious defects early in the war (one of the results of which was the propensity of liberty boat hulls to shear under minimal forces).

I know shell shatter was discussed wrt CMBO & CMBB. Just thought I'd bring it up again since the armor and shell grogs are here.

[DevilDog]

I read something interesting this morning in a non-grog book that I hadn't heard before. Don't know if is accurate or not. The book claimed that for over a year, possibly up to two years the Brits didn't know the Germans had face hardened armor which caused Brit AP shot to shatter. Inability to spot the impacting AP rounds (I don't remember the reason why) lead the Brits to mistakenly think they simply had accuracy problems and they worked on improving marksmanship, instead of realizing there was a serious technology gap.

Is it possible that the discrepancy between CMAK and RL reports is the result of projectile shatter? I know the Allied shells had serious defects early in the war (one of the results of which was the propensity of liberty boat hulls to shear under minimal forces).

I know shell shatter was discussed wrt CMBO & CMBB. Just thought I'd bring it up again since the armor and shell grogs are here.

[Andreas]

Kenneth Macksey in 'Afrika Korps' gives the info as follows.

Originally 2-pdr could penetrate Panzer III and IV out to 1,000 yards. Then in March 1942 face-hardened improved armour turns up, and suddenly the 2-pdr fails over 300 out to 1,200 due to shatter, then penetrates to 1,800 (sometimes) and over that fails again, consistently.

Unfortunately he gives no source for that.

[Andreas]

Kenneth Macksey in 'Afrika Korps' gives the info as follows.

Originally 2-pdr could penetrate Panzer III and IV out to 1,000 yards. Then in March 1942 face-hardened improved armour turns up, and suddenly the 2-pdr fails over 300 out to 1,200 due to shatter, then penetrates to 1,800 (sometimes) and over that fails again, consistently.

Unfortunately he gives no source for that.

[Guest Mike]

Originally posted by The Green Rascal:

LOL thanks Billybob, nice typo from me. They were of course Cruiser IIIs not Crusader IIIs

ROFL - well that makes it quite clear!!

[Guest Mike]

Originally posted by The Green Rascal:

LOL thanks Billybob, nice typo from me. They were of course Cruiser IIIs not Crusader IIIs

ROFL - well that makes it quite clear!!

[flamingknives]

Originally posted by The Green Rascal:

LOL thanks Billybob, nice typo from me. They were of course Cruiser IIIs not Crusader IIIs

So that's an A13, Mk I. (Cruiser Mk III)

Crikey, the nomenclature is complicated around then.

[flamingknives]

Originally posted by The Green Rascal:

LOL thanks Billybob, nice typo from me. They were of course Cruiser IIIs not Crusader IIIs

So that's an A13, Mk I. (Cruiser Mk III)

Crikey, the nomenclature is complicated around then.

[dragonwagon]

Hmmm,Osprey Military has a few lines worth adding to the mix.[The 9th Lancers of 2nd armoured states that the 2pdr. shot bounced off Panzer IIIs and the Germans regarded it with contempt,while their 50mm rounds would go straight through a Crusader.]

Also from the 10th Hussars[They were particulary scathing about the performance of the 2pdr. gun,claiming that 500 yds. was the maximum effective range against a Panzer III which ,with it's 50mm gun, was effective at 1000 yards or more.](Future discussian.....50mm.)

At the time ,Summer of 1942 ,Gazala,is when the quotes above came from.I'm assuming by then that most of, if not all the Mark IIIs are Hs.

Shall be interesting to see how this goes.

[dragonwagon]

Hmmm,Osprey Military has a few lines worth adding to the mix.[The 9th Lancers of 2nd armoured states that the 2pdr. shot bounced off Panzer IIIs and the Germans regarded it with contempt,while their 50mm rounds would go straight through a Crusader.]

Also from the 10th Hussars[They were particulary scathing about the performance of the 2pdr. gun,claiming that 500 yds. was the maximum effective range against a Panzer III which ,with it's 50mm gun, was effective at 1000 yards or more.](Future discussian.....50mm.)

At the time ,Summer of 1942 ,Gazala,is when the quotes above came from.I'm assuming by then that most of, if not all the Mark IIIs are Hs.

Shall be interesting to see how this goes.

[The Green Rascal]

Ahem - back to the 2pdr then I remembered I had Ian Hogg's 20thC artillery book and have looked them up in there. Disappointingly he doesn't give penetration figures, but he does make this comment in the text:

Britain continued making them in 1941 in order to build strength with a known gun before shifting to a bigger weapon. This was a considerable handicap to British forces in North Africa when they were confronted with German tanks in 1941-1942

If he views them as a handicap, we can probably put him in the ineffective camp as well.

However I have also searched the Imperial War Museum's online archive and was suprised by this 1942 document. After a brief and sometimes unkind description it states

Typical performance when firing the 2lb AP Shot was 42mm penetration at 1000yds, at angle of 30 degrees, with a maximum range of 8000yds.

That is actually above CMAKs penetration figures. Unfortunately it doesn't specify the source, but if anyone is passing IWM Duxford in the next few days can you please pop in and have a look at it

So IIRC at the moment we have the Cairo tests from Rexford, Pitt specifically ruling out it's effectiveness over 500m, Hogg's implications, Dragonwagon's very useful quotes, in opposition to Bastables report, Andreas' Macksey quote and now this IWM document. To muddy the water further we have possible mistakes in data tables and projectile shatter issues.

Should keep us going for a little while longer then

[ December 04, 2003, 06:47 PM: Message edited by: The Green Rascal ]

[The Green Rascal]

Ahem - back to the 2pdr then I remembered I had Ian Hogg's 20thC artillery book and have looked them up in there. Disappointingly he doesn't give penetration figures, but he does make this comment in the text:

Britain continued making them in 1941 in order to build strength with a known gun before shifting to a bigger weapon. This was a considerable handicap to British forces in North Africa when they were confronted with German tanks in 1941-1942

If he views them as a handicap, we can probably put him in the ineffective camp as well.

However I have also searched the Imperial War Museum's online archive and was suprised by this 1942 document. After a brief and sometimes unkind description it states

Typical performance when firing the 2lb AP Shot was 42mm penetration at 1000yds, at angle of 30 degrees, with a maximum range of 8000yds.

That is actually above CMAKs penetration figures. Unfortunately it doesn't specify the source, but if anyone is passing IWM Duxford in the next few days can you please pop in and have a look at it

So IIRC at the moment we have the Cairo tests from Rexford, Pitt specifically ruling out it's effectiveness over 500m, Hogg's implications, Dragonwagon's very useful quotes, in opposition to Bastables report, Andreas' Macksey quote and now this IWM document. To muddy the water further we have possible mistakes in data tables and projectile shatter issues.

Should keep us going for a little while longer then

[ December 04, 2003, 06:47 PM: Message edited by: The Green Rascal ]

[The Green Rascal]

Aha! Breakthrough, I just realised MikeyD's figures are wrong. The 2pdr in CMAK has the following stats:

0

Degrees:...82mm@100m...52mm@500m...44mm@1000m...24mm@2000m.

30

Degrees:...52mm@100m...38mm@500m...36mm@1000m...24mm@2000m.

Now then, this agrees with the penetration figures used for the Cairo tests, and the IWM document, so our 2pdr penetration numbers are straight and a big cheer for CMAK is due

However it still does not explain why our first group of sources are saying that the 2pdr was ineffective v's PzIIIs over 500m and our second group are saying that it could kill them.

So, I think we need to look at the PzIII armour instead, that must be the area where the discrepancy arises. I have a horrible feeling that it may turn into another 'curved' armour problem, as the turret front on PZIIIs is all '30mm Curved'.

If the 30mm Curved is resisting at not much above 30mm, then the 2pdr penetrations above make it obvious that in CMAK PZIIIs are toast up to 1500m. If it resists as the Cairo test and Rexford advises at 52mm, then we get exactly a 500m cut off for penetrations, which would tie up a lot of our quotes nicely.

So then, if anyone is till following the plot, I am now proposing that the 30mm Curved armour is where the problem is. And as for why I'm harping on, well it directly affects the gameplay and accuracy of the simulation. At the moment you don't need to close the range as it seems they were forced to do historically.

[The Green Rascal]

Aha! Breakthrough, I just realised MikeyD's figures are wrong. The 2pdr in CMAK has the following stats:

0

Degrees:...82mm@100m...52mm@500m...44mm@1000m...24mm@2000m.

30

Degrees:...52mm@100m...38mm@500m...36mm@1000m...24mm@2000m.

Now then, this agrees with the penetration figures used for the Cairo tests, and the IWM document, so our 2pdr penetration numbers are straight and a big cheer for CMAK is due

However it still does not explain why our first group of sources are saying that the 2pdr was ineffective v's PzIIIs over 500m and our second group are saying that it could kill them.

So, I think we need to look at the PzIII armour instead, that must be the area where the discrepancy arises. I have a horrible feeling that it may turn into another 'curved' armour problem, as the turret front on PZIIIs is all '30mm Curved'.

If the 30mm Curved is resisting at not much above 30mm, then the 2pdr penetrations above make it obvious that in CMAK PZIIIs are toast up to 1500m. If it resists as the Cairo test and Rexford advises at 52mm, then we get exactly a 500m cut off for penetrations, which would tie up a lot of our quotes nicely.

So then, if anyone is till following the plot, I am now proposing that the 30mm Curved armour is where the problem is. And as for why I'm harping on, well it directly affects the gameplay and accuracy of the simulation. At the moment you don't need to close the range as it seems they were forced to do historically.

[Michael Emrys]

I suspect the reason they had to close the range historically was because they almost never got a straight-on shot, so you should be using the 30° tables. So with something like 60mm of frontal armor for the PzIIIs, they would have to close inside of 100 meters it looks like to me. The mantlet could be penetrated by a lucky shot above 1,000 meters however.

Michael

[Michael Emrys]

I suspect the reason they had to close the range historically was because they almost never got a straight-on shot, so you should be using the 30° tables. So with something like 60mm of frontal armor for the PzIIIs, they would have to close inside of 100 meters it looks like to me. The mantlet could be penetrated by a lucky shot above 1,000 meters however.

Michael

[Sir Uber General]

I'm also under the impression that the brits improved their 2pdr ammo (capped it to help defeat FHA) during the african campaign which could lead to some discrepency here.

[Sir Uber General]

I'm also under the impression that the brits improved their 2pdr ammo (capped it to help defeat FHA) during the african campaign which could lead to some discrepency here.

[Guest Mike]

It occurs to em that a lot of the problem here is that impressions of combat are being taken as fact.

If the 2 pdr could occasionally defeat P-3 turret armour at 1000m, at a range where the Crusaders and Cruisers were ALWAYS being penetrated by the 50mm L42 then the Brits are hardly likely to consider the 2 pdr effective.

The British would consider the gun effective at a range where they could RELIABLY KO the Germans - ie in enough numbers to make it obvious.

A few KO-ed German tanks might easily not be noticed, and might be easily recovered, whereas large numbers of KO'ed British tanks were completely obvious and often lost to teh axis advance!

[rune]

At 1000, CMAK has it penetrating 44mm

This fits with this web site:

http://www.wwiivehicles.com/html/britain/PenetrationTables.htm

and also with this web site

http://www.btinternet.com/~ian.a.paterson/equipartillery.htm

and this web site

http://www.ra39-45.pwp.blueyonder.co.uk/guns/page4.html

According to Encyclopedia of German Tanks of World War Two, front turret in the H and G was 30 @ 13, and 30@15, and the gun manlet itself was 37@0-45.

Also found some Naval AA gun reports ont he 2 pdr AA gun, armor penetration is marked higher then the above, could it be due to the difference of type of plate?

Rune

[Guest Mike]

It occurs to em that a lot of the problem here is that impressions of combat are being taken as fact.

If the 2 pdr could occasionally defeat P-3 turret armour at 1000m, at a range where the Crusaders and Cruisers were ALWAYS being penetrated by the 50mm L42 then the Brits are hardly likely to consider the 2 pdr effective.

The British would consider the gun effective at a range where they could RELIABLY KO the Germans - ie in enough numbers to make it obvious.

A few KO-ed German tanks might easily not be noticed, and might be easily recovered, whereas large numbers of KO'ed British tanks were completely obvious and often lost to teh axis advance!

[rune]

At 1000, CMAK has it penetrating 44mm

This fits with this web site:

http://www.wwiivehicles.com/html/britain/PenetrationTables.htm

and also with this web site

http://www.btinternet.com/~ian.a.paterson/equipartillery.htm

and this web site

http://www.ra39-45.pwp.blueyonder.co.uk/guns/page4.html

According to Encyclopedia of German Tanks of World War Two, front turret in the H and G was 30 @ 13, and 30@15, and the gun manlet itself was 37@0-45.

Also found some Naval AA gun reports ont he 2 pdr AA gun, armor penetration is marked higher then the above, could it be due to the difference of type of plate?

Rune