155 mm gun T7

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155mm L/40 T7
The T7 as mounted on the T30E1 heavy tank
TypeTank gun
Place of originUnited States
Service history
Used byUnited States
Production history
Produced1940s
VariantsT7, T7E1
Specifications
Mass2,384 kg (5,256 lb)
Length7.74 m (25 ft 5 in)
Barrel length7.1976 m (23 ft 7.37 in) (L/41.4)

Caliber155 mm (6.1 in)
Rate of fire2 rpm
Muzzle velocity701–1,106 m/s (2,300–3,630 ft/s)
Maximum firing rangeProject cancelled before maximum range tests occurred

The 155mm L/40 T7 was an American rifled tank gun developed in 1945.[1] The T7 was to be the main armament for the T30 Heavy Tank, but only a handful were produced due to the T30 project being cancelled after trials in the late 1940s.

The T7 used two-part separated ammunition like the 105mm T5E1 gun on the T29 Heavy Tank.[2] It had a low velocity of only 701 m/s (2,300 ft/s) compared to the 120mm T53 on the T34 Heavy Tank (945 m/s) and the 105mm T5E1 on the T29 Heavy Tank (945 m/s).[3] However, the 43 kg (95 lbs) High-Explosive shell (HE) and high-velocity armour-piercing (HVAP) was demonstrated to have a powerful demolition effect. Testing concluded before completion when the T30 project was cancelled in the late 1940s.

Penetration comparison[edit]

Calculated penetration (30 degrees)[4]
Ammunition type Muzzle velocity Penetration (mm)
500 m 1000 m 1500 m 2000 m 2500 m 3000 m
M112B1 (AP) 701 m/s (2,300 ft/s) 215 213 203 211 195 187
T43 (Mod.) (AP) 774 m/s (2,540 ft/s) 254 243 236 226 215 203
T35 (HVAP) 1,106 m/s (3,630 ft/s) 392 355 340 314 292 276
M107 (HE) 945 m/s (3,100 ft/s) 54 54 54 54 54 54

Variants[edit]

  • T7 - Standard model
  • T7E1 - T7 modified for use with a power rammer and ejection equipment.

References[edit]

  1. ^ Hunnicutt, Richard P. (1988). Firepower: A History of the American Heavy Tank. Brattleboro, Vermont: Echo Point Books & Media. p. 228. ISBN 978-0891413042.
  2. ^ Hunnicutt, Richard P. (1988). Firepower: A History of the American Heavy Tank. Brattleboro, Vermont: Echo Point Books & Media. p. 88. ISBN 978-0891413042.
  3. ^ Hunnicutt, Richard P. (1988). Firepower: A History of the American Heavy Tank. Brattleboro, Vermont: Echo Point Books & Media. pp. 224–5. ISBN 978-0891413042.
  4. ^ Bird, Lorrin Rexford; Livingston, Robert D. (2001). WWII Ballistics: Armor and Gunnery. Overmatch Press. p. 61.