150 discarding sabot.

[chuckfourth]

Hi All
Looking at http://www.tarrif.net/.
It seems that unit 079 15cm sFH 18 that currently has HE only actually had a a HEAT and apds round.
also the HEAT penetrations of unit 033 7.5cm leFK 18 seems to be 7 not 5.
Best Regards Chuck.

[CharlesM]

The Germans only ever considered discarding sabot rounds to increase the range of artillery. None was used in action as far as I am aware. This was NOT APDS, which only Britain and the US 57mm AT ever used (reverse Lend-Lease).

[Mobhack]

Actually, from reading Hogg some time back, we actually produced a quantity of 6pdr APCR. This never seems to have been used - and seems to be the HVAP ammo the USA towed AT (which were poor relations of the mech TD) recieved as reversed lend-lease.

6pdr APDS was never officially supplied to the USA, but was likely unofficially traded for a few C-rations etc

Cheers
Andy

[CharlesM]

11,000+ APDS rounds sounds fired by US forces sounds like a lot of trading unofficially. I am sure it was supplied openly. The figures came from research that ASL guru Bob McNamara did at Aberdeen PG - I think. The 6-pdr APCR round was found to be "balistically unstable" and was not used in NW Europe but might have been used by some British units in the last month of the Tunisian campaign, for example at Longstop hill, as there is reference to a new AP type round in the action reports, and some sources (Fletcher's book on the Churchill published as Mr Churchill's Tank) also mentions an "HVAP" round (horribly vague, imprecise term) being issued to some Churchill units.

6-pdr APDS figures dug out - 1st US Army fired 6302 rounds June-July 1944, and 11,428 by VE Day. 5th US rmy in Italy got APDS in December 1944 and fired 180 rounds by VE Day.

[Mobhack]

The usage figures for APDS by the USA are certainly news to me.

Cheers
Andy

[DRG]

CharlesM said:6-pdr APDS figures dug out - 1st US Army fired 6302 rounds June-July 1944, and 11,428 by VE Day. 5th US rmy in Italy got APDS in December 1944 and fired 180 rounds by VE Day.

Could you tell us where these numbers were "dug out" from please ?

Don

[cbo]

CharlesM said:
The figures came from research that ASL guru Bob McNamara did at Aberdeen PG - I think.

As I understand it, the idea that the US had APDS (and HE?) for their 57mm AT-guns was included in some old ASL manual without any references to where it came from.

Then ca. 2002, Kurt Laughlin found a document at USAMHI giving some APDS expenditure figures, which seems to have been compiled in 1953. Still, the paper had no publication date, author, or publishing agency, so where the data originally came from is anybodys guess.

These are the figures found by Kurt:

Aug 44 - 7% (of 68,506 = 4800 rounds)
Nov 44 - 1% (of 43,024 = 430)
Jan 45 - 3% (of 84,233 = 2500)
Feb 45 - 2% (of 79,849 = 1600)
Mar 45 - 3% (of 75,331 = 2300)
Apr 45 - 3% (of 52,281 = 1600)
May 45 - 2% (of 9,349 = 190)
For all other months the table lists 0%

It is of course worth noticing, that the 13,000 rounds fired is only 3% of the 413,000 57mm rounds fired and that the number of APDS rounds available for each 57mm gun was 6 - for the entire campaign from June 1944 to May 1945 - and that included training.

But they were used in combat. If you look in the SAIC Anti-Armor Defense Data Study from 1990 (vol. III) (download from http://stinet.dtic.mil/ ) on page 21, you can find the following:

The nature of the terrain and the fog which blanketed the area compelled LtCol Daniel to place his anti-tank assets well forward, in order to have sufficient visibility to support the foxhole lines. He set up three 57mm antitank
guns covering the road running east to Bullingen, and supported them with three M-1O self-propelled tank
destroyers mounting 3-inch guns. He sent three more AT guns to bolster the main line of resistance, or MLR, in the E and F Co areas. Each of the 57mm guns had, as part of its ammunition supply, seven to ten rounds of British discarding sabot (DS) ammunition, which the British had given to the regiment before D-Day.' 3 These rounds used a disposable sleeve, or sabot, around the penetrator for the British 2-pounder gun. The result was a lighter projectile with increased velocity, about 4200 ft/sec vice 2900 ft/sec
for the normal 57mi round. With this velocity, a DS round could penetrate approximately six inches (154mm) of armor at a 300 slope. 14 This made the obsolescent 57mm gun more effective, particularly against the heavy Panther tank
and Jagdpanther tank destroyer.

The source for the information is appears to be one Capt. Rivette who commanded an anti-tank company in the battle.

It is worth noticing, that they got the rounds before the invasion from the British, which might suggest, that a quantity was supplied to the US forces in the UK before June 1944 and that was all they ever got, unless they could swap some along the way.

Of course, APDS rounds may not have been evenly distributed, so if this issue of APDS to US units is to be applied to the game, it might be considered making one gun with a few rounds and one without.

The Germans did actually make some anti-tank APDS rounds, including one for the 15cm sFH but it was not the one presented on the on the site Chuck is referring to.

"Spr.Gr 42 TS" means "Sprenggranate 42 Treibspiegel" which translates to "High-explosive shell 42 discarding sabot" This was a high-explosive round with 4kg of explosive and a total weight of some 30kg, which apparently used the subcaliber design to increase range.

The real item was the "15cm PzGr. 39 TS" - "150mm anti-tank shell 39 discarding sabot". This appears to have used a standard 88mm PzGr 39 APCBC round supported in the 150mm barrel by a base and shoulder ring. Apparently a round of some 10kg with 60 grams of explosive. This type of projectile is described on page 266 in Hoggs book on German Artillery. It is highly unlikely that it was ever fielded, however.

cbo

[Marek_Tucan]

Wait, do I get it correct from the report that the 6pdr APDS was just 2pdr shot in sabot? That'd mean it didn't use as much precious metals as tungsten carbide APCR did, thus cheaper and easier to manufacture but with possible worse properties? Was it the same system with 17pdr APDS?

[DRG]

cbo said:
<snip>
These are the figures found by Kurt:

Aug 44 - 7% (of 68,506 = 4800 rounds)
Nov 44 - 1% (of 43,024 = 430)
Jan 45 - 3% (of 84,233 = 2500)
Feb 45 - 2% (of 79,849 = 1600)
Mar 45 - 3% (of 75,331 = 2300)
Apr 45 - 3% (of 52,281 = 1600)
May 45 - 2% (of 9,349 = 190)
For all other months the table lists 0%

It is of course worth noticing, that the 13,000 rounds fired is only 3% of the 413,000 57mm rounds fired and that the number of APDS rounds available for each 57mm gun was 6 - for the entire campaign from June 1944 to May 1945 - and that included training.
cbo

Given that info, allowing 3% of the ammo loadout to be APDS would seem fair. That would give 2-3 sabot rounds to each 57mm AT-Gun and would also require a slight adjustment to the service dates of a unit or two.

Don

[cbo]

Marek_Tucan said:
Wait, do I get it correct from the report that the 6pdr APDS was just 2pdr shot in sabot? That'd mean it didn't use as much precious metals as tungsten carbide APCR did, thus cheaper and easier to manufacture but with possible worse properties? Was it the same system with 17pdr APDS?

Nope, both had proper tungsten penetrators as far as I know. I'm sure that the report is just repeating the impression that Capt. Rivette had at the time. IIRC normal 2-pdr AP already had issues with fragmentation on impact at normal velocities and would not have been able to achieve the performance figures quoted for 6-pdr APDS.

cbo