The L-11 76.2 mm tank gun was a Soviet tank gun, used on the earliest models of the T-34 Model 1940 medium tank and KV-1 Model 1939 heavy tank during World War II.
| L-11 76.2 mm tank gun | |
|---|---|
 T-34 Model 1940 with L-11 gun | |
| Type | Tank gun |
| Place of origin | Soviet Union |
| Service history | |
| Used by |  Soviet Union Nazi Germany |
| Wars | World War II |
| Production history | |
| Designer | IA Makhanov |
| Designed | 1938 |
| Manufacturer | Kirov Plant |
| Produced | 1939-1941 |
| Variants | L-17 |
| Specifications | |
| Barrel length | 2.3 m (7 ft 7 in) L/30.5[1] |
| Shell | Fixed QF 76.2 × 385 mm. R |
| Shell weight | 6.5 kg (14 lb 5 oz) |
| Caliber | 76.2 mm (3.00 in)[1] |
| Breech | Semi-automatic vertical sliding-wedge |
| Recoil | Hydro-pneumatic |
| Elevation | 2° to 25° |
| Traverse | 360°[2] |
| Rate of fire | 6-7 rpm |
| Muzzle velocity | 613 m/s (2,010 ft/s) |
| Maximum firing range | 5.6 km (3.5 mi)[2] |
| 7.62 cm FK 250(r) | |
|---|---|
| Type | Field gun |
| Place of origin | Soviet Union |
| Service history | |
| Used by | Soviet Union Nazi Germany |
| Wars | World War II |
| Production history | |
| Designer | Kirov Plant |
| Produced | 1941-1942 |
| Specifications | |
| Mass | 1,325 kg (2,921 lb) |
| Barrel length | 2.3 m (7 ft 7 in) L/30.5[1] |
| Shell | Fixed QF 76.2 × 385 mm. R |
| Shell weight | 6.5 kg (14 lb 5 oz) |
| Caliber | 76.2 mm (3.00 in)[1] |
| Breech | Semi-automatic vertical sliding-wedge |
| Recoil | Hydro-pneumatic |
| Carriage | Split-trail |
| Elevation | -5° to +37° |
| Traverse | 55°[1] |
| Rate of fire | 6-7 rpm |
| Muzzle velocity | 613 m/s (2,010 ft/s) |
| Maximum firing range | 5.6 km (3.5 mi)[1] |
History edit
The L-11 was designed in 1938 by IA Makhanov of the SKB-4 design bureau at the Kirov Plant in Leningrad. It was 30.5 calibers long,[3] had a semi-automatic vertical sliding-wedge breech, used fixed quick-fire 76.2 x 385 mm R ammunition and had a hydro-pneumatic recoil mechanism.
It has been claimed that the L-11 was based on the 76 mm air-defense gun M1914/15 designed by VV Tarnovsky and F. F. Lender.[4] What can be said is that both the M1914/15 and L-11 had similar lengths, similar muzzle velocities (592 m/s vs 613 m/s), were built in the same factory and fired the same ammunition.
Through a combination of administrative interference by Marshal Grigory Kulik and bureaucratic inertia, the first models of the T-34 and KV-1 were both armed with the L-11. Testing of both tanks highlighted an undesirable situation where both a medium tank and heavy tank were equal in firepower and neither had the firepower necessary to defeat a foreign tank of similar capabilities. Although an acceptable tank gun by the standards of the time the L-11 did not have a substantial performance advantage over foreign designs. Therefore, the L-11 was a stopgap until improved guns for the T-34 and KV-1 could be produced. An early favorite to replace the L-11 was a modified version of the 76 mm air defense gun M1931, but delays and difficulties saw it passed over despite excellent performance.[4]
During 1941 the L-11 was replaced on T-34 production lines by the 42.5 caliber F-34 and on KV-1 production lines by the 31.5 caliber F-32. Despite being considered a superior design the performance of the F-32 gun was not substantially better than the L-11 and inferior to the F-34 gun used on the T-34. Eventually, the F-32 gun was replaced on the KV-1 production lines by a modified version of the F-34 gun called the ZiS-5, finally giving the T-34 and KV-1 parity in firepower.[4]
Variants edit
L-17 casemate gun edit
During the 1930s the Red Army proposed creation of a new 76 mm casemate gun capable of withstanding a direct hit from a 76 mm armor-piercing projectile fired from a distance of 400 m (1,300 ft) or the explosion of a 203 mm (8.0 in) high-explosive projectile at a distance of 1 m (3 ft 3 in) from the pillbox.
The design bureau of the Kirov Plant under the leadership of IA Makhanov responded by creating a variant of the L-11 which it called the L-17. The L-17 was mounted in a heavily armored gun mantlet with the barrel inside of an armored tube. In May 1939, the Kirov plant received an order for six-hundred L-17 guns. During testing between September 29 and October 8, 1939 the L-17 withstood the impact of a 76 mm armor piercing projectile fired from a M1902/30 field gun at a velocity of 529–547 m (1,736–1,795 ft) at a distance of 50 m (160 ft). The first L-17's were installed in June 1940 in the Kamenets-Podilsky fortified area.[5]
Field gun conversion edit
During 1941-1942 a field gun based on the L-11 was introduced. It consisted of an L-11 barrel on the split-trail carriage used by the ZiS-3. This adaptation was probably done to address the huge losses of artillery suffered during the summer of 1941 and to use surplus L-11 barrels. The Soviet designation for this gun is not known, but the Germans referred to them as the 7.62 cm FK 250(r).[1]
Comparison of guns edit
| Gun | Model | L-11 | F-32 | F-34 |
|---|---|---|---|---|
| Length (calibres) | L/30.5 | L/31.5 | L/42.5 | |
| F-534 high explosive (HE) | weight (kg) | 6.23 | 6.23 | 6.23 |
| muzzle velocity (m/s) | 610 | 613 | 680 | |
| OF-350 high explosive fragmentation (HE-Frag) |
weight (kg) | 6.21 | 6.21 | 6.21 |
| muzzle velocity (m/s) | 610 | 638 | 680 | |
| BR-353A high explosive anti-tank (HEAT) |
weight (kg) | 3.9 | 3.9 | 3.9 |
| muzzle velocity (m/s) | ? | ? | 325 | |
| penetration (mm) | 75 | 75 | 75 | |
| Armour-piercing (AP) | weight (kg) | 6.51 | 6.51 | 6.3 |
| muzzle velocity (m/s) | 612 | 613 | 680 | |
| penetration at 500 m (mm) | ? | 60 | ? | |
| penetration at 1,000 m (mm) | 50 | 50 | 60 | |
| BR-350/BR-350A armour-piercing high explosive (APHE) |
weight (kg) | 6.3 | 6.3 | 6.3 |
| muzzle velocity (m/s) | 612 | 613 | 655 | |
| penetration at 500 m (mm) | 62 | ? | 69 | |
| penetration at 1,000 m (mm) | 56 | ? | 61 | |
| BR-350P armour-piercing, composite rigid (APCR) |
weight (kg) | ? | ? | 3.0 |
| muzzle velocity (m/s) | ? | ? | 965 | |
| penetration at 500 m (mm) | ? | ? | 92 | |
| penetration at 1,000 m (mm) | ? | ? | 60 |
Notes edit
- ^ a b c d e f g Chamberlain, Peter (1975). Light and medium field artillery. Gander, Terry. New York: Arco. p. 62. ISBN 0668038209. OCLC 2067331.
- ^ a b c amvas. "Guns and Ammo of Soviet Tanks". www.armchairgeneral.com. Retrieved 2017-09-17.
- ^ Zaloga, Steve (1994). T-34/76 Medium Tank 1941-45. Osprey Publishing. p. 41. ISBN 978-1-85532-382-7.
- ^ a b c "Tank Archives: "Minor Modernization": T-150". Tank Archives. 2016-02-05. Retrieved 2017-09-17.
- ^ "Дело о казематной пушке / Гений советской артиллерии. Триумф и трагедия В.Грабина". www.plam.ru. Retrieved 2017-09-17.
- ^ Zaloga, Steve (1984). Soviet tanks and combat vehicles of World War Two. Grandsen, James. London: Arms and Armour Press. p. 225. ISBN 0853686068. OCLC 12810882.
References edit
- Chamberlain, Peter. Gander Terry. 1975. Light and medium field artillery. New York: Arco. ISBN 0668038209.
- Zaloga, Steve. 1994. T-34/76 Medium Tank 1941-45. Osprey Publishing. ISBN 978-1-85532-382-7
- Zaloga, Steve. Grandsen, James. 1984. Soviet tanks and combat vehicles of World War Two. London: Arms and Armour Press. p225. ISBN 0853686068.