German discarding sabot rounds

critical mass · #16

I wonder what the accuracy of these were? It would be another antitank solution for weapons like the StuH and Wespe and the artillery howitzers. The HEAT round for these weapons would be powerful also but somewhat range/velocity limited.

Accuracy was reasonable.
According to BAMA RH8 -1326´s tabulation titled "Übersicht über TS-Geschosse im Vergleich zu Normalgeschossen" dated 29th of sep. 1944:

service 10cm Pzgr39 TS (subcalibre: 7.5cm Pzgr39 for leFH18)
muzzle velocity: 765m/s (fired from le FH18)
reliable Penetration (Vh for five consecutive penetrations) at 60°:
100m: 99mm RHA
500m: 88mm RHA
1000m: 76mm RHA
Accuracy:
50% zone of impacts at 1000m:
Höhe: 40cm
Seite: 50cm
(for comparison, the same table lists l.FH18 firing 10cm Gr.39 Hl. Ausf.C with a 50% zone of impacts at 1000m:
Höhe: 100cm & Seite: 43cm)

15cm Pzgr39 TS for sFH18:
muzzle velocity: 880m/s (fired from s FH18 with subcalibre 8.8cm Pzgr39)
reliable Penetration (Vh for five consecutive penetrations) at 60°:
100m: 155mm RHA
500m: 140mm RHA
1000m: 126mm RHA
Accuracy:
50% zone of impacts at 1000m:
Höhe: 50cm
Seite: 57cm
notice: 10.000 15cm Pzgr39 TS rounds were operationally field tested at the Eastern Front from 20.10.1944 to 1.11.1944.

12.8cm Pzgr39 TS for PAK44 and KwK44:
muzzle velocity: 1230m/s (fired from PAK44 with subcalibre 8.8cm Pzgr39)
reliable Penetration (Vh for five consecutive penetrations) at 60°:
1000m: 264mm RHA
2000m: 230mm RHA
Accuracy:
no data

according to the commentaries, the accuracy was lower for TS projectiles with a larger difference between bore- and subcalibre.

I have attached the engeneering drawing for the 10cm Pzgr39 TS as in service by end of 1944 in this memo (primary source, unpublished).

Yoozername · #17

Great stuff! Thanks for sharing. I invited you from that awful 'Archive Awareness' website. Don't waste your time with that guy.

critical mass · #18

Don´t mind, he put me on a list in his site which bans me from posting there anymore. Too much critique to handle, I guess.

Zünder · #19

@criticall mass: i found Rh8-1326 in my archives, unfortunately without the drawings, so thanks for that drawing ! How many pages is the entire 1326 file ?
I don’t think it is a drawing of a 10,5 cm Pzgr 39 (Ts).
In Rh8-1326 there’s a list of drawings, and the only drawing of a 10,5 cm Pzgr is the 10,5/7,5 cm Pzgr. Ts mbs (Müdungsbremsensicher).
The differences between 10,5 cm Pzgr 39 (Ts). and 10,5/7,5 cm Pzgr. Ts mbs is significant: different sabot (flat, 3 piece disc type/ 1 piece pot type), different front ring (3 segment ring/ 1 piece resin ring) and fuze (Bd.Z. 5103*/ Bd.Z 5103/1)
In june 1943 the 10,5 cm Pzgr 39 was added to the list of officially used shells, see the D/460/2+ Geschossringbuch, shells had to be made according to drawing nr 13 C 1426.
However, the 10,5 cm Pzgr 39 (Ts), together with 10,5 cm Spgr. 42 (Ts), 15 cm Pzgr. 39 (Ts) and 15 cm Spgr. 42 (Ts) were only to be fired from guns that did not have a muzzlebreak.
By July 1943 Krupp, Rheinmetall and Bochumer Verein were still working on the “mbs”shells, shells that could be fired by guns with a muzzlebreak.

Production:
I found a productionsheet for the 10,5 cm Spgr. 42 Ts: 4500 produced in December 1943 and no other shells in stock.
Similar numbers for the 15 cm Spgr. 42 Ts, with 5100 produced in January 1944 of which only 4000 were eventually accepted, no other shells in stock.

critical mass · #20

Zünder,

You are, of course correct that the drawing shows the -mbs version of the 10cm Pzgr TS. I shouldn´t post late in the night.
My copy of RH-8-1326 contains 406 pages, it´s actually a two-part compilation of documents.

The documents states that the operational field trials conducted during 1944 on the Eastern Front with these TS weapons (in particular for 10.5cm le.FH 18 and 15cm s.FH18) apparently included muzzle break guns. Only after these field trials and the experiences with fouling of the muzzle breaks -at times- were the original -TS projectiles removed from guns with muzzle breaks.

It´s noteworthy that the 10cm Pzgr 39 TS as well as the 15cm Pzrg 39 TS was tabulated under the category
"eingeführt"
-and thus were, together with the HE-variant cleared for service and not experimental anymore.
A later document dated 27th of january 1945 claimed that 10000 specimen of the improved Ausf. II of the 15cm/8.8cm Spgr. 42 TS (HE)were readied for another troop trial in mid february 1945 after 800 shells were fired on the prooving ground without failure.

The 12.8cm Pzgr. TS was listed under finnished development
"fertig entwickelt"
-a simpler version was under development, which also worked for PAK 80 and -81.
Production was intended to be as simple as possible. "production" in this case means "conversion".

There was also a very modern, experimental 10.5cm/4.5cm APDSFS (fin stabilized, armour piercing hard cored- sub calibre, discarding sabot) tested in autumn 1944 (V0: 1060m/s at pmax:3090kg/cm^2) to be fired from a 105mm smooth bore.

It appears that the problems of some of the production 88mm Pzgr39 to stay intact at velocities in excess of 1000m/s caused hesitations to proceed with sub calibre AP programme for 128mm guns as the ordinary full calibre 12.8cm Pzgr43 was more reliable in staying intact against plates much thicker than 200mm @30°. Only at long range (>2500m) was the performance of the 12.8cm/8.8cm Pzgr39 TS therefore consistently better, causing the higher level to again request studies of the feasability of hard cored TS-sub calibre projectiles (APCR-DS), instead of APCBC-DS.

Yoozername · #21

I would think the StuH would be the natural candidate for these since it did not use a muzzle brake? i have a document that seems to show that the HE version used a KWK 42 high explosive projectile for some reason. i am not sure what the intent was for this sub-HE round? Except, perhaps, to have a high velocity high explosive round?

Zünder · #22

@Critical mass: you are referring to the 10,5 cm/4,5 cm UKP/Peenemünde Pfeilgeschoss for 10,5 cm Flak 39 ?
I am not sure that was a AP round, i examined a complete specimen and own remains of another one and there was no indication that they were AP.
The tip unscrewed and was not hardened, the projectile itself filled with tar.
I know this shell was fired from a 10,5 cm Flak 39 smooth bore, but i recently acquired 1 of the ringsegments for this shelltype and it clearly was shot through a rifled barrel.

@Yoozername: i think the idea behind the sub HE-round was the longer range, the same reason why so many sub-cal were developed for the Flak guns.

Zünder,

www.wk2ammo.com