Variable Penetration of 88mm Ammo

[rexford]

In response to a number of posts on the Saumur Intranets site regarding the impact of HE burster size on 88mm APCBC penetration, Richard Simmie sent an e-mail to me which points out a number of important factors regarding 88mm Flak effectiveness during Barbarossa. The following is a summary of Richard's research findings.

The following information is taken from Thomas Jentz's "Dreaded Threat".

In 1938 the 8.8 Flak 18 was considered for firing against Ground targets, specifically armoured/concrete Pillboxes and enclosures. Armour piercing ammunition would be in service from this time onwards and consisted of the 8.8 cm Panzergranate weighing 9.5 kg (9.65kg is also stated in the text) with Armour piercing cap and ballistic cap with High explosive filler of 160 grams. Muzzle velocity is listed as 810 m/s from the L/56 barrel of the Flak 18 and Flak 36/37.

During early 1942 the penetration ability was improved with the introduction of the Pzgr.39 of 10.2 kg weight with reduced HE filler of 59 grams. Muzzle velocity was 800 m/s.

30 degrees Penetration

88mm Pzgr APCBC- Early 88mm Flak Ammo

100....500.....1000.....1500......2000m

98.....93........87.......80......72mm

30 degrees Penetration

88mm Pzgr 39 APCBC- Tiger E Round

100....500.....1000.....1500....2000m

127....117.....106.......96......88mm

The early Blitzkrieg up to early 1942 saw the use of the large capacity Pzgr with penetration less than 100mm at 30 degrees. In May 1941 Hitler had demanded a Tank weapon capable of penetrating 100mm at about 1500m and the improved Pzgr.39 could approach that. The 88 was retained for the Tiger I instead of installing the 75 L/70.

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In terms of 0 degree penetration, we used the slope effects in our book on WW II BALLISTICS with the 30 degree figures noted above and arrived at the following 0 degree figures for early 88mm Flak APCBC and small capacity 88mm APCBC (as used on Tiger E):

0 Degree Penetration

Early 88mm Flak large HE capacity APCBC

100m...500m...1000m...1500m....2000m

123....116....108.....99.......88

0 Degree Penetration

Tiger E Smaller HE Capacity 88mm APCBC

100m...500m...1000m...1500m....2000m

162....149....134.....120......109

(162).(151)..(138)...(126)....(116) (Our book)

The 88mm Flak APCBC which fought the KV and T34 tanks during 1941 and early 1942 was less effective than the round fired by the Tiger E. A British firing report shows that the later 88mm Flak round with a large capacity HE burster (and 9.54 kg weight) penetrated 8% less than the Tiger E APCBC, but the above data shows about a 23% average inferiority for early 88mm Flak ammo.

We believe that the early Barbarossa 88mm APCBC round not only contained a larger HE burster than the Tiger round and weighed less, but was softer steel which resulted in about an 8% drop in penetration for burster size and reduced weight, and about a 15% decrease due to less effective metal.

The stories where 88mm Flak hits on KV tanks resulted in no damage may be due to nose shatter (shatter gap), which occurred with U.S. projectiles when the metal hardness fell below a given threshold and the round overpenetrated the armor resistance.

[rexford]

The assumption that early war German ammo was inferior to later stuff also explains why 50mm AP penetrates less than 50mm APC, despite:

1. 50mm AP does not have an armor piercing cap, which absorbs about 12% of penetration

2. 50mm AP has a smaller HE burster than 50mm APC

Here are 30° penetration figures for 50mm APC and AP at selected ranges:

50mm L42 AP, 53mm at 100m, 43mm at 500m

50mm L42 APC, 55mm at 100m, 47mm at 500m

50mm AP should outpenetrate APC by about 14% or so, but is inferior.

The use of soft metal would also explain why 37L45 AP and 75L24 APCBC penetrate so little when they are compared to later German ammo like 75L43.

Jentz' data for 75L43 APCBC penetration may also be based on tests with early ammo.

Jeff Duquette posted a story some time ago where 88mm Flak units were having their shots shatter against KV and T34 armor at 2000+ meters, and it took 10 shots per kill.

If early 88mm Flak rounds were used, and there must have been alot of them during 1942 and 1943, the penetration at 2000m would not be sufficient to get many penetrations against KV-I and T34 front hull, and KV-I turret front.

The data provided by Richard Simmie answers many questions, and he did a great job digging into the material.

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This is a comparison of published 30° penetration for 88L56 APCBC and an explanation of what it seems to represent:

88L56 Early War Large HE Burster-88mm Flak (9.54kg projectile)

98mm at 100m, 93mm at 500m, 87mm at 1000m

88L56 Later War Large HE Burster-88mm Flak

(9.54 kg projectile)

120mm at 100m, 110mm at 500m, 100mm at 1000m

88L56 Later War Small HE Burster-Tiger and Flak (10.2 kg projectile)

127mm at 100m, 117mm at 500m, 106mm at 1000m

Early war 88mm ammo combines a large burster with what appears to be inferior steel to penetrate considerably less than later war ammo.

88L56 Flak ammo at 9.54 kg penetrates about 6% less than Tiger ammo due to less weight and greater burster size.

[rexford]

KV-2 had 110mm rounded mantlet and 75mm at 30° driver plate, which would give the 88mm Flak units some difficulty during 1941 if overpenetrating rounds shattered on driver plate and and mantlet hits took place at 500+ meters range.