12.8 cm Pak 44

12.8 cm Pak 44
Pak 44 in firing position
Type	Heavy Anti-Tank Gun
Place of origin	Nazi Germany
Service history
In service	1944—1945
Used by	Nazi Germany
Wars	World War II
Production history
Designer	Krupp
Designed	1943
Manufacturer	Krupp
Produced	1944
Number built	51
Specifications
Weight	10,160 kg (22,400 lb)
Barrel length	7.023 m (20 ft) L/55
Shell	semi-fixed
Shell weight	28 kg (62 lb) (HE) 28.3 kg (62 lb) (AP)
Caliber	128 millimetres (5.0 in)
Breech	semi-automatic horizontal sliding-block
Recoil	Hydropneumatic
Carriage	cruciform (some were split trail)
Elevation	-7° 51' to +45° 27'
Traverse	360° (some were about 90°, or less)
Muzzle velocity	950 m/s (3,100 ft/s)
Maximum firing range	24,410 m (26,700 yd)

The 12.8 cm Pak 44 L/55 (PaK, (Ger.) Panzerabwehrkanone) was a German heavy anti-tank gun used during World War II. It was designed as a result of experiences on the Eastern front in 1943. The German army had encountered the Russian 122 mm guns and had issued a requirement for a similar weapon. Development initially concentrated on a field gun known as the Kanone K 44. However, once heavier Russian armour, such as the IS-2, started to appear the design requirements were altered to include an anti-armour role.

The Pak 44 had short to medium-range performance similar to the 8.8 cm Pak 43, but the 12.8 cm Pak 44 better maintained its anti-tank performance over long to extreme-long ranges (1800–2700+ metres) while also doubling as an effective field gun when firing HE.

The choice of 128 mm was made because of the availability of tooling due to the use of this caliber for naval weapons. Design contracts were awarded to Rheinmetall Borsig and Krupp. The first prototype guns were delivered for testing in late 1944. Rheinmetall began development of a variant of the 128 mm FlaK gun, whilst Krupp opted to design a new weapon from the ground up. After initial tests, the Rheinmetall design was dropped and development continued with the Krupp design. However, the service tests showed that a towed anti-tank gun weighing nearly 11 tonnes was impractical, so the towed design was terminated.

Approximately 50 barrels and breeches were used on existing carriages. The weapon that used the ex-French GPF-T carriage was known as the K 81/1, while the K 81/2 used the ex-Russian carriage. Both of these designs were rushed, and were too heavy, making them cumbersome to deploy. In 1943, a design programme using the Pak 44 as its starting point was started for a gun to mount on the Jagdtiger (Sd.Kfz. 186) and the Maus super-heavy tank. This weapon, of which approximately 100 were made. was known both as the Pak 44 and Pak 80 / Panzerjägerkanone Pjk 80. Performance was identical to the initial design.