2.8 cm sPzB 41

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2,8 cm schwere Panzerbüchse 41
sPzB 41 captured by the British Army, 1942.
Type	anti-tank gun
Place of origin	Germany
Service history
In service	1941-1945
Used by	Germany
Wars	WWII
Production history
Designed	1940
Manufacturer	Mauser-Werke AG
Produced	1940-1943
Number built	2,797
Specifications
Weight	229 kg
Length	2,690 mm
Barrel length	overall: 1,730 mm (with muzzle brake)
Width	965 mm
Height	838 mm
Crew	3
Caliber	28/20 mm
Breech	horizontal block
Recoil	hydrospring
Carriage	split trail
Elevation	-5° to 30°
Traverse:	70°
Rate of fire	up to 30 rounds per minute
Muzzle velocity	1,400 m/s
Effective range	500 m

2,8 cm sPzB 41 was a German anti-tank weapon working on the squeeze bore principle. Officially classified as heavy anti-tank rifle (schwere Panzerbüchse), it would be better described, and is widely referred to as a light anti-tank gun^[1].

Contents 1 Description 2 Development and production history 3 Organization and employment 4 Variants 5 Summary 6 Ammunition 7 Notes 8 References

[edit] 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 most interesting feature of the design was its cone-shaped barrel, with caliber reducing from 28 mm at the chamber end to only 20 mm at the muzzle. The projectile was fitted with two external flanges; as it proceeded toward the muzzle, the flanges were squeezed into it (hence the name "squeeze bore"). 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 was closing 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 35/36 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 tyres 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.

[edit] Development and production history

The squeeze bore principle was first patented in 1903 by a German designer Karl Puff. In 1920s and 1930s another German engineer, Gerlich, conducted experiments with squeeze 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 Gerat 231 or MK.8202. In June-July 1940 an experimental bunch of 94 (other sources say 30) pieces was given to the army for trials. The trials resulted in some modifications and in 1941 a mass production of what became 2,8 cm schwere Panzerbüchse 41 started. One piece costed 4,520 reichsmarks (for the sake of comparison, one 5 cm PaK 38 gun costed 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

[edit] Organization and employment

sPzB 41 was used by some motorized divisions and by some light infantry, mountain and 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 North African Campaign and on the Western Front in 1944-1945.

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

[edit] Variants

External images
	sPzB 41. [1]
	Airborne variant (with shield). [2]
	SdKfz 250/11. [3]
	SdKfz 221 mounting sPzB 41. [4]

• 2,8 cm sPzB 41 leFl 41 (2,8 cm schwere Panzerbüchse 41 auf leichterfeldlafette 41) - variant developed for paratrooper units. Used lightweight carriages without suspension; wheels were replaced by small rollers; shield was typically removed. The resulting weapon weighed only 139 kg (118 kg without rollers). The carriage supported a 360° field of fire, and elevation ranged from -15° to 25°.
• 2,8 cm KwK 42 - tank gun modification. A bunch of 24 was produced. It is not clear if they were ever used.

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

[edit] Summary

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:

• The barrel was hard to manufacture and had short service life (about 500 shots)
• Very weak fragmentation shell
• Use of tungsten for armor-piercing shells
• Short effective range
• Relatively weak behind-armour effect.

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.

[edit] 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]

[edit] Notes

1. ^ E.g. see 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.

[edit] References

• Shirokorad A. B. - The God of War of the Third Reich - M. AST, 2002 (Широкорад А. Б. - Бог войны Третьего рейха. — М.,ООО Издательство АСТ, 2002., ISBN 978-5-17-015302-2)
• Ivanov A. - Artillery of Germany in Second World War - SPb Neva, 2003 (Иванов А. - Артиллерия Германии во Второй Мировой войне. — СПб., Издательский дом «Нева», 2003., ISBN 978-5-7654-2634-0)
• Zaloga, Steven J., Brian Delf - US Anti-tank Artillery 1941-45 (2005) Osprey Publishing (New Vanguard 107), ISBN 978-1-84176-690-4.
• Guns vs Armour: German Guns up to 30mm calibre

 

German artillery of World War II
Tank guns
2 cm KwK 30 | 3.7 cm KwK 36 | 3.7 cm KwK 38(t) | 5 cm KwK 38 | 5 cm KwK 39 7.5 cm KwK 37 | 7.5 cm KwK 40 | 7.5 cm KwK 42 | 8.8 cm KwK 36 | 8.8 cm KwK 43
Anti-tank guns
2.8 cm sPzB 41 | 3.7 cm PaK 36 | 4.2 cm PaK 41 | 5 cm PaK 38 | 7.5 cm PaK 97/38 7.5 cm PaK 40 | 7.5 cm PaK 41 | 7.62 cm PaK 36(r) | 8.8 cm PaK 43 | 12.8 cm PaK 44
Field, Medium and Heavy guns
7.5 cm Le.IG 18/Le.GebIG 18/IG L/13 | 7.5 cm IG 37 | 10.5 cm leFH 18 | 15 cm sIG 33 15 cm sFH 18 | 21 cm Mrs 18
Other vehicle mounted
7.5 cm PaK 39 | 7.5 cm PaK 40 | 7.5 cm PaK 42 | 8.8 cm PaK 43 | 12.8 cm PaK 44
Anti-aircraft guns
2 cm FlaK 30/38/Flakvierling | 3.7 cm FlaK 36/37/43 | 8.8 cm FlaK 18/36/37/41 | 10.5 cm FlaK 38 12.8 cm FlaK 40