12,8cm K43 Selbstfahrlafette Rheinmetall January 7th, 1943

12,8cm K 43 Selbstfahrlafette Rheinmetall-Borsig - January 7th, 1943 (Drawing Copyright Hilary Louis Doyle)

In early 1942 Wa.Prüf 4, the German organization in charge of field artillery, put forward a design requirement for a vehicle to move heavy artillery. The main stipulation was that it should use parts from the new Panther medium tank. A similar competition was already underway for a vehicle to move lighter field artillery, such as 10,5cm guns, using the Geschützwagen III/IV chassis. This had inspired Wa.Prüf 4 to do the same for a vehicle to move heavier 12,8cm and 15cm artillery pieces, as the Geschützwagen III/IV was too small to handle them. The guns in question were the 12,8cm K 43 and 15cm sFH 43. The sFH 43 was a projected improvement on the 15cm sFH 18, the new gun was to use bagged propellant and had a screw-type breech. The 12,8cm K 43 is unknown in most literature, but is presumably a predecessor to the 12,8cm K 44 L/55. Neither of these cannons were ever built.

In order to keep weight down, the designs were to be open-topped. Prototypes were to be built using Panther parts, but it was projected that any serial production vehicles would be made using the Panther II chassis. This idea was discarded when the Panther II was cancelled in June of 1943.

Both Krupp and Rheinmetall-Borsig took part in this design competition. All designs were able to be transported by rail with a few adjustments; and all could carry at least 30 rounds of ammunition, however Rheinmetall’s design had trouble with this.

January 7th, 1943 DesignEdit

After their original entries (1) (2) were met with lukewarm response, Rheinmetall-Borsig decided to scrap them and instead persue a different design. On January 7th, 1943, Rheinmetall produced three more designs. In reality these were the same vehicle, but with different armaments.

The vehicle had a centrally mounted, 360 degree rotating, dismountable turret. The chassis was that of a Panther, extended to a wheelbase of 4,220mm.
12,8cm K43 Selbstfahrlafette Rheinmetall January 7th, 1943 Mockup 2

12,8cm Selbstfahrlafette Rheinmetall-Borsig - January 7th, 1943 Wooden Mockup

Drawing H-SkB 80449 for 15cm sFH 43 (Sfl.) Rheinmetall-Borsig

Drawing H-SkB 80450 for 12,8cm K 43 (Sfl.) Rheinmetall-Borsig

Drawing H-SkB 80451 for 12,8cm P 43 (Sfl.) Rheinmetall-Borsig

This version of the 15cm sFH 43 (Sfl.) had a slightly longer gun barrel at L/34. It fired a 43.5 kilogram projectile at 600 meters per second up to 15,000 meters. The 12,8cm P 43 was a high-performance (presumably) dedicated anti-tank gun. It fired a sub-caliber 14 kilogram shell at 1,175 meters per second. Rheinmetall said they could have a prototype ready by August 1st if they received the needed Panther parts by April 1st, 1943. A wooden mockup was built of one of the 12,8cm-armed versions, but this design did not advance any further.

On or around February 24th, 1943, Rheinmetall's entry for the Selbstfahrlafette für 12,8cm K 43 und 15cm sFH 43 Project was assigned the cover name "Skorpion". This name probably covered the January 7th design, but since it is not known when Rhenmetall abandoned it it cannot be said for certain.


  1. Special Panzer Variants: Development - Production - Operations - Hilary Louis Doyle and Walter J. Spielberger, 2007
  2. Panther Variants 1942-1945 - Osprey New Vanguard, 1997
  3. Panther & Its Variants - Walter J. Spielberger, 1993