delcyros
Tech Sergeant
Gents,
I have not much time these days but throught that this would be worth sharing here. In mid 1943, shortage of tungsten issued a production memorandum banning the production of Pzgr40/43 APCR shot. The following outlines are my synthesis of archival material, sources which remained unpublished as far as I am aware off.
Production instead shifted to the more improved, small filler APCBC-HE (Pzgr.39 series). While the better heat tretament, blunter nose, thicker cap and more solid projectile walls reulted in a generally superior AP-penetrator, able to negotiate more difficult impact schock, the new AP changed little for all the odd lower verlocity guns, struggling to defeat T34, KV1 and alike.
To adress these issues, R&D was heading into two main directions:
A) improved HEAT projectiles suitable for low velocity guns (better standoff fuzes, elemination of spin velocity, fin stabilization)
B) APCBCDS projectiles [armor piercing capped, ballistic capped, discarding sabot with small filler and base fuze).
Because tungsten was not available in the required quantities, the regular Pzgr 39 was assumed as sub calibre shot in the latter case. Small, discarding sabots were added to the base and fwd bourrolet (called "Treibspiegel").
This allowed the following combinations (list dated to nov. 1944):
for 105mm leFH18:
10cm Pzrg TS:
subcalibre: 75mm Pzgr 39 (7.7kg weight), velocity: 765m/s, reliable penetration (5 out of 5): 99mm RHA @ 30° (122mm @ 0°) and 100m, roughly comparable to PAK40 in performance.13,500 projectiles manufactured and by nov. 1944 in regular service
in development:
10cm Pzrg TS mbs:
subcalibre: 75mm Pzgr 39 (7.7kg weight), velocity: 765m/s, reliable penetration (5 out of 5): 99mm RHA @ 30° (122mm @ 0°) and 100m, roughly comparable to PAK40 in performance, this variant was muzzle break proof
for 15cm sFh18 / Hummel et al:
15cm Pzrg 39 TS:
subcalibre: 88mm Pzgr 39 (15.0kg weight), velocity: 880m/s, reliable penetration (5 out of 5) at 30° against RHA:
100m: 155mm (191mm vertical)
500m: 140mm (172mm vertical)
1000m: 126mm (155mm vertical)
2000m: 104mm (128mm vertical)
Roughly comparable to 75mm KWK42 / PAK42. This projectile was adopted for service in mid 1944 but not produced. In development was a simplified version (15cm Pzgr 39 TS vereinfacht) with similar performance but suited for mass production.
for 12.8cm KWK44 /PAK 44:
12.8cm Pzrg TS
subcalibre: 88mm Pzgr 39 (13.1kg weight), velocity: 1230m/s, reliable penetration (5 out of 5) at 30° against RHA:
1000m: 200mm if breaking up / 264mm if staying intact*
2000m: 200mm if breaking up / 220mm if staying intact*
3000m: 178mm (always intact)
4000m: 140mm (always intact)
*) break up occurred on the Hillersleben prooving ground against plates thicker than 200mm for the 88mm subcalibre AP in roughly half the times. Projectiles from the manufacturer Bochumer Verein always stayed intact, even against 305mm RHA plates.
The latter numbers translate to the following penetration against vertical RHA plate:
1000m: 200mm* / 325mm
2000m: 200mm* / 276mm
3000m: 200mm* / 219mm
4000m: 172mm (always intact)
-if the projectile is presumed to stay intact, which is possible at the very high velocities for the projectiles made by Bochumer Verein, it could penetrate about 300mm RHA @ 30°, 370mm RHA @ 0° and 140mm* RHA @ 60° at 100m.
There was still no need to field the 128mm TS projectile due to the APCBC taking care of everything then encountered.
However, the 12.8cm Pzgr.39 TS would be required to deal with the post war IS-4 and IS-7 designs. The drawing of this projectile dated to 1944 is attached in this memo. To make it clear, it contains a minor error by conflating cap with and not seperating against the projectile nose (those who carefully watch the contour see where the cap starts).
best regards,
delc
I have not much time these days but throught that this would be worth sharing here. In mid 1943, shortage of tungsten issued a production memorandum banning the production of Pzgr40/43 APCR shot. The following outlines are my synthesis of archival material, sources which remained unpublished as far as I am aware off.
Production instead shifted to the more improved, small filler APCBC-HE (Pzgr.39 series). While the better heat tretament, blunter nose, thicker cap and more solid projectile walls reulted in a generally superior AP-penetrator, able to negotiate more difficult impact schock, the new AP changed little for all the odd lower verlocity guns, struggling to defeat T34, KV1 and alike.
To adress these issues, R&D was heading into two main directions:
A) improved HEAT projectiles suitable for low velocity guns (better standoff fuzes, elemination of spin velocity, fin stabilization)
B) APCBCDS projectiles [armor piercing capped, ballistic capped, discarding sabot with small filler and base fuze).
Because tungsten was not available in the required quantities, the regular Pzgr 39 was assumed as sub calibre shot in the latter case. Small, discarding sabots were added to the base and fwd bourrolet (called "Treibspiegel").
This allowed the following combinations (list dated to nov. 1944):
for 105mm leFH18:
10cm Pzrg TS:
subcalibre: 75mm Pzgr 39 (7.7kg weight), velocity: 765m/s, reliable penetration (5 out of 5): 99mm RHA @ 30° (122mm @ 0°) and 100m, roughly comparable to PAK40 in performance.13,500 projectiles manufactured and by nov. 1944 in regular service
in development:
10cm Pzrg TS mbs:
subcalibre: 75mm Pzgr 39 (7.7kg weight), velocity: 765m/s, reliable penetration (5 out of 5): 99mm RHA @ 30° (122mm @ 0°) and 100m, roughly comparable to PAK40 in performance, this variant was muzzle break proof
for 15cm sFh18 / Hummel et al:
15cm Pzrg 39 TS:
subcalibre: 88mm Pzgr 39 (15.0kg weight), velocity: 880m/s, reliable penetration (5 out of 5) at 30° against RHA:
100m: 155mm (191mm vertical)
500m: 140mm (172mm vertical)
1000m: 126mm (155mm vertical)
2000m: 104mm (128mm vertical)
Roughly comparable to 75mm KWK42 / PAK42. This projectile was adopted for service in mid 1944 but not produced. In development was a simplified version (15cm Pzgr 39 TS vereinfacht) with similar performance but suited for mass production.
for 12.8cm KWK44 /PAK 44:
12.8cm Pzrg TS
subcalibre: 88mm Pzgr 39 (13.1kg weight), velocity: 1230m/s, reliable penetration (5 out of 5) at 30° against RHA:
1000m: 200mm if breaking up / 264mm if staying intact*
2000m: 200mm if breaking up / 220mm if staying intact*
3000m: 178mm (always intact)
4000m: 140mm (always intact)
*) break up occurred on the Hillersleben prooving ground against plates thicker than 200mm for the 88mm subcalibre AP in roughly half the times. Projectiles from the manufacturer Bochumer Verein always stayed intact, even against 305mm RHA plates.
The latter numbers translate to the following penetration against vertical RHA plate:
1000m: 200mm* / 325mm
2000m: 200mm* / 276mm
3000m: 200mm* / 219mm
4000m: 172mm (always intact)
-if the projectile is presumed to stay intact, which is possible at the very high velocities for the projectiles made by Bochumer Verein, it could penetrate about 300mm RHA @ 30°, 370mm RHA @ 0° and 140mm* RHA @ 60° at 100m.
There was still no need to field the 128mm TS projectile due to the APCBC taking care of everything then encountered.
However, the 12.8cm Pzgr.39 TS would be required to deal with the post war IS-4 and IS-7 designs. The drawing of this projectile dated to 1944 is attached in this memo. To make it clear, it contains a minor error by conflating cap with and not seperating against the projectile nose (those who carefully watch the contour see where the cap starts).
best regards,
delc
Attachments
Last edited:
