Some tungsten info

[Tiger]

Taken from "Sherman" by R.P. Hunnicutt (highly recomended but a bit pricey at $100). The authoratative reference on the Sherman.

"The standard 76mm armor piercing round was the APC M62. This was a capped projectile fitted with a ballistic cap (APCBC) to reduce the drag and improve long range performance. Late production rounds were explosive loaded using a base detonation fuze. After the appearance of heavily armored German vehicles, a rush development program introduced the M93 hypervelocity armor piercing (HVAP) solid shot. This was a lightwieght shot with an aluminum body and a tungsten carbide core. Frequently referred to as armor piercing composite rigid (APCR), the low weight resulted in a muzzle velocity of 3400 ft/sec compared to 2600 ft/sec for the APC M62. The high velocity combined with the high core density greatly increased the armor penetration. Although the velocity decreased more rapidly with the lightweight projectile, its armor piercing performance still exceeded the that of the standard round at ranges of greater than 2000 yards. Rushed into production for both the 76mm and 3 inch guns, the HVAP ammunition was used effectively during the final months of the war."

"In August [1944] a few rounds of the new 76mm HVAP were rushed to France and tests were conducted near Isigny against six captured Panthers. The tests showed that the new ammunition was extremely accurate and a great improvement over the old APC M62, but it could not penetrate the Panther's frontal plate at ranges over 300 yards. Production of the new ammunition was also limited to only 10,000 rounds per month which meant that it could only be used on an emergency basis."

-john

[KiwiJoe]

Thats strange.. cause in CM 76mm (t) rounds can take the Panther out with front hull/turret shots at over 1500m.

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by KiwiJoe:

Thats strange.. cause in CM 76mm (t) rounds can take the Panther out with front hull/turret shots at over 1500m.<HR></BLOCKQUOTE>

If youre seeing a glacis penetration by 76mm APCR-T at 1500ms, then something is wrong, as even 17lb APDS, & 90mm APC all failed regurly vs the glacis @ at as low as 300ms.

The Front turret could be penetrated at 700ms by 76mm APC, the mantlet at 100ms with APCR-T the vulnerable ranges go up vs the Front turret vs the glacis is another story, of course this is real world results not game.

Regards, John Waters

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[This message has been edited by PzKpfw 1 (edited 09-28-2000).]

[Dittohead]

Good info, Any info on British tungsten availability and production out there?

[Tiger]

Armoured Firepower by Peter Gudgin:

not copied verbatum though;

"The British were the first to start using the tungsten rounds along with their "littlejohn" adaptor on the muzzle, which squeezed their 2-pdr down to 30mm to increase velocity. However while giving good increased penetration at shorter ranges, this squeeze reduced the velocity at longer ranges (wasted energy). The Germans also tried a similiar adapter along with tungsten core rounds (taper-bore gun). Shortage of tungsten stopped the Germans from developing this further....

The British 17-pdr also used a discarding sabot round, which led to what's in use today. A outer shell (the sabot)that disentegrates when it reaches the end of the barrel, allowing the denser inner core of tungsten to fly at the target at a much greater velocity. However the resulting debri from the discarding sabot endagered troops who were in front of the tank and caused damage to any muzzel attachments."

I have no info on the availability, but as it was new technology without all the kinks worked out, it stands to reason usage might be rare.

-john

[KiwiJoe]

Im just looking at the numbers. In CM at 1000m the 76mm t round can penetrate 175mm. The Panther's front hull is 80/55 but thats only at 85% quality. So its really 68/55. That = rouhly 130mm/0. Which means the 76mm t round can punch threw it with no problems. In fact the 76mm t can penetrate 124mm @ 2000m which gives it a slight chance even at that range.

[Tiger]

The data I'm looking at shows the HVAP M93 penetration @ 1000 yards to be 5.3 inches (135mm). Convert yards to meters (914.4 meters) and 175mm seems a bit much even for this round. At 500 yards (457.2 meters) the HVAP round penetrates 157mm. Still 18mm short of the 175mm @ 1000m. This is based on the M1A1 gun. There is only a slight increase using the M1A2 at longer ranges. This is against homgeneous armor sloped at 30 degrees obliquility.

-john

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by KiwiJoe:

Im just looking at the numbers. In CM at 1000m the 76mm t round can penetrate 175mm. The Panther's front hull is 80/55 but thats only at 85% quality. So its really 68/55. That = rouhly 130mm/0. Which means the 76mm t round can punch threw it with no problems. In fact the 76mm t can penetrate 124mm @ 2000m which gives it a slight chance even at that range.<HR></BLOCKQUOTE>

Joe I assume your refering to CM's data here. Theirs is a bit more involved in this

then the numbers refelect, Ie, the M93 APCR-T round is actualy forced to take a longer penetration path, because of its sharper tip, WW2 APCR-T & APDS etc, suffered performance penalties vs oblique armor Ie, the Panther's Glacis of 80mm @ 55^ is a perfect example.

Thats why despite the numbers given for 76mm APCR-T & 17LB APDS both rounds consistently failed vs the Panthers glacis even at 100yrds as did 90mm APCBC & APCR-T.

Regard, John Waters

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[This message has been edited by PzKpfw 1 (edited 09-28-2000).]

[Simon Fox]

Yes, John is right the effect of slope on penetration cannot be modelled by simple geometry. Sure up to about 30 degrees slope it's not too bad. But that 55 degree slope on the Panther glacis is nasty and 68/55 is not equivalent to 130/0 at all. To further complicate matters the projectile shape also comes into it so a APCBC round may be slower than a APDS round but might 'bite' better in sloped armour.

Then again if it is FH armour and the round shatters instead of ricocheting then the vehicle is more vulnerable....can of worms isn't it

As for British APDS, Vorotyntsev has kindly provided me with the following data on standard gun loadouts dated May 1944. He got it from Claus Bonneson.

6pdr

75% APCBC, 6% APDS and 19% HE

17pdr

60% APCBC, 6% APDS and 34% HE

The 6pdr APDS was available in quantity from prior to June '44. The 17pdr APDS was pretty sporadic until August '44 when it was too available in quantity

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"Fatso-the battlers' prince"

[IntelWeenie]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Tiger:

"The British were the first to start using the tungsten rounds along with their "littlejohn" adaptor on the muzzle, which squeezed their 2-pdr down to 30mm to increase velocity.<HR></BLOCKQUOTE>

An interesting side note about the "littlejohn" adapter was that it screwed onto the muzzle of an otherwise normal 2-pdr (sort of like a silencer on a pistol). However, since the regular AP ammo did not squeeze down to 30mm, crews were instructed to remove the adapter when they wished to fire normal AP. They would then reattach it when they wished to fire the sqeeze rounds (all of this during a firefight, of course ). Needless to say, most crews left the adapter off all the time.

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Canada: Where men were men, unless they were horses.

-Dudley Do-right

[KiwiJoe]

So CM models sharp tip vs blunt tip effectiveness agianst armour angle? If so what rounds have blunt tips and which have sharp? From what I understand, blunt rounds actually tip up a bit on contact with high angle armour and dig in and downwards making them far more likely to penetrate. Where as sharp tip rounds tend to bounce off vs angles but are better agianst a flat 90 degree face. And Q 2 for u hardasses ... which tanks have face hardened armour, which from what I understand, causes the round to shatter on impact. I think from memory this was more common on german tanks?

[PzKpfw 1]

<BLOCKQUOTE>quote:</font><HR>Originally posted by KiwiJoe:

So CM models sharp tip vs blunt tip effectiveness agianst armour angle? If so what rounds have blunt tips and which have sharp? <HR></BLOCKQUOTE>

Hi Joe, I realy have no idea if CM models the AOI dependant performance of the various penetrator heads, my comments pertained to RL data, perhaphs Charles or Steve can answer that.

<BLOCKQUOTE>quote:</font><HR> From what I understand, blunt rounds actually tip up a bit on contact with high angle armour and dig in and downwards making them far more likely to penetrate. Where as sharp tip rounds tend to bounce off vs angles but are better agianst a flat 90 degree face. And Q 2 for u hardasses ... which tanks have face hardened armour, which from what I understand, causes the round to shatter on impact. I think from memory this was more common on german tanks?<HR></BLOCKQUOTE>

Below is a snip from a conversation Robert Livingston & Paul are haveing on Tankers list concerning this subject, that some may find imformative:

<BLOCKQUOTE>quote:</font><HR>

In reference to Paul's observation that the obliquity mutiplier for 30deg hits seems to increase for 8.8 cm L/71 APCBC, in comparison to US 90mm APCBC, I think that can be explained because the German shot is

penetrating a lot more steel than the US shot, and so its slope multiplier increases.

We have found that, as a general rule, as the T/D ratio increases, the slope effects become more drastic. This seems to hold true for most WWII penetrators. We have also found that the more pointed-nose AP, which is more pointed than APCBC of the same diameter

(that is, higher CRH, or Caliber/Radius/Head) suffers more when impacting oblique armor. This effect is probably due to the longer lever arm of the long pointed nose, so the shot is more easily deflected. <HR></BLOCKQUOTE>

German tank armor used FH extensively Ie, the Panthers nose was FH, its ball mg mount etc. You can find more on German FH practices in the 88 Lacking punch thread starting on page 9 or 10 IIRC.

Regards, John Waters

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[This message has been edited by PzKpfw 1 (edited 09-29-2000).]