2.8 cm sPzB 41

2.8 cm schwere Panzerbüchse 41

sPzB 41 at the Canadian War Museum in Ottawa
Type Anti-tank gun
Place of origin  Nazi Germany
Service history
In service 1941–1945
Used by  Nazi Germany
Wars World War II
Production history
Designed 1940
Manufacturer Mauser-Werke AG
Produced 1940–1943
Number built 2,797
Specifications
Weight 229 kg (505 lbs)
Length 2.69 m (8 ft 10 in)
Barrel length overall:1.73 m (5 ft 8 in) (with muzzle brake)
Width 96.5 cm (3 ft 2 in)
Height 83.8 cm (2 ft 9 in)
Crew 3

Caliber 28/20 mm (1.10/.78 in)
Breech horizontal block
Recoil hydrospring
Carriage split trail
Elevation -5° to 30°
Traverse 70°
Rate of fire up to 30 rpm
Muzzle velocity 1,400 m/s (4,593 ft/s)
Effective range 500 m (547 yds)

2.8 cm schwere Panzerbüchse 41 (sPzB 41) or "Panzerbüchse 41" was a German anti-tank weapon working on the squeeze bore principle. Officially classified as heavy anti-tank rifle (German: schwere Panzerbüchse), it would be better described, and is widely referred to, as a light anti-tank gun[1].

Contents

Description

Although the sPzB 41 was classified as a heavy anti-tank rifle, its construction was much more typical of an anti-tank gun. Like the latter, it had a recoil mechanism, carriage and shield. The only significant feature the weapon had in common with anti-tank rifles was lack of elevation and traverse mechanisms—the light barrel could be easily manipulated manually.

The design was based on a cone-shaped barrel, with the caliber reducing from 28 mm at the chamber end to only 20 mm at the muzzle. The projectile carried two external flanges; as it proceeded toward the muzzle, the flanges were squeezed down, decreasing the diameter with the result that pressure did not drop off as quickly and the projectile was propelled to a higher velocity. The barrel construction resulted in very high muzzle velocity: up to 1,400 m/s. The bore was fitted with a muzzle brake. The horizontal sliding block breech was "quarter-automatic": it closed automatically once a shell was loaded. The gun was equipped with open sight for distances up to 500 m; telescopic sight ZF 1х11 from 3.7 cm Pak 36 anti-tank gun could also be fitted.

The recoil system consisted of hydraulic recoil buffer and spring-driven recuperator. The carriage was of split trail type, with suspension. Wheels with rubber tires could be removed, making the gun significantly lower and therefore easier to conceal; the process took 30–40 seconds. The gun construction allowed toolless dismantling to five pieces, the heaviest of which weighed 62 kg.

Development and production history

The cone-bore principle was first patented in 1903 by a German designer Karl Puff. In the 1920s and 1930s another German engineer, Gerlich, conducted experiments with coned-bore barrels which resulted in an experimental 7 mm anti-tank rifle with muzzle velocity of 1,800 m/s.

Based on these works, in 1939–1940 Mauser-Werke AG developed a 28/20 mm anti-tank weapon initially designated Gerät 231 or MK.8202. In June–July 1940 an experimental batch of 94 (other sources say 30) pieces was given to the army for trials. The trials resulted in some modifications and in 1941 mass production of what became 2.8 cm schwere Panzerbüchse 41 started. One piece cost 4,520 Reichsmarks (for the sake of comparison, one 5 cm Pak 38 gun cost 10,600 Reichsmarks). The last gun was built in 1943; the main reason for the discontinuance was lack of tungsten for projectiles.

Production of sPzB 41, pcs.[2]
1940 1941 1942 1943 Total
94 349 1030 1324 2797
Production of ammunition for sPzB 41, thousands.[2]
Shell type 1940 1941 1942 1943 Total
Fragmentation - 9.2 373.3 130.1 512.6
Armour-piercing 156.2 889.5 270.0 278.1 1602.8

Organization and employment

sPzB 41 was used by some motorized divisions and by some Jäger (light infantry), Gebirgsjäger (mountain) and Fallschirmjäger (paratrooper) units. Some guns were supplied to anti-tank and sapper units.[3] The weapon was employed on the Eastern Front from the beginning of the hostilities (on 1 June Wehrmacht possessed 183 pieces) until the end of the war and also saw combat in the North African Campaign and on the Western Front in 1944–1945.

Short-range shots from sPzB 41 could penetrate most World War II armour; a lucky shot could even damage heavy tanks such as KV-1 and IS-2 (at least in one instance a projectile penetrated the lower front plate of the latter).

Variants

The sPzb 41 was also mounted on SdKfz 250 half-tracks; this variant was designated SdKfz 250/11. A few were mounted on SdKfz 221 armored cars.

Service

Squeeze bore guns saw only limited use in World War II. Manufacturing of such weapons was impossible without advanced technologies and high production standards. The only country except Germany to bring such weapons to mass production was Britain with Littlejohn adaptor which—although not a gun by its own right—used the same principle. An attempt of Soviet design bureau headed by V. G. Grabin in 1940 failed because of technological problems[2]. In the US, reports about the sPzB 41 inspired a series of experiments with 28/20 barrels and taper bore adaptors for the 37mm Gun M3; the work started in September 1941 and continued throughout the war, with no practical results[4].

sPzB 41 combined good anti-armor performance at short range and high rate of fire with small, lightweight (for anti-tank gun), dismantleable construction. However, it also had several shortcomings, such as:

Some authors that criticize the sPzB 41 concentrate mainly on short service life of its barrel. However, a chance of survival after 500 short-range shots was slim anyway. It should also be noted that high-velocity guns with "normal" barrel construction also had short service life, e.g. for the Soviet 57-mm ZiS-2 it was about 1,000 shots. In the end, the factor that brought the production of sPzB 41 to a halt was the shortage of tungsten.

Ammunition

There were two shell models for sPzB 41: the armor-piercing 2.8 cm Pzgr.41 and the fragmentation 2.8 cm Sprg.41.

The Pzgr.41 had a tungsten carbide core, a soft steel casing and a magnesium alloy ballistic cap. The core was 40 mm long and 10.9 mm in diameter and contained about 9.1% of tungsten.

Available ammunition[2]
Type Model Weight, kg Filler Muzzle velocity, m/s Range, m
APCNR-T 2.8 cm Pzgr.41 0.125 - 1,430 500
Fragmentation 2.8 cm Sprg.41 0.093 5 g, phlegmatized PETN 1,400 1,000
Armour penetration table
APCNR-T projectile 2.8 cm Pzgr.41
Distance, m Meet angle 60°, mm Meet angle 90°, mm
100 52[2] – 69[5] 75[3]
300 46[2]
400 40[3]
500 40[2] – 52[5]

Notes

  1. ^ E.g. US War Department Intelligence Bulletin, Nov. 1944
  2. ^ a b c d e f g Shirokorad A. B. The God of War of the Third Reich.
  3. ^ a b c Ivanov A. Artillery of Germany in Second World War.
  4. ^ Zaloga, Delf. US Anti-tank Artillery 1941–45, p 6–7.
  5. ^ a b Guns vs Armour, from Hogg, Ian V. German Artillery of World War Two.

References

External Images

Tapered Bore Gives This German Gun Its High-Velocity December 1942 article revealing new German antitank gun with excellent drawing explaining "squeeze" principle.