7.5 cm Infanteriegeschütz 37

The 7.5 cm Infanteriegeschütz 37 (7.5 cm IG 37) was an infantry support gun, used by Germany during World War II. The guns were originally designated 7.5 cm PaK 37. The IG 37s were manufactured, beginning in late 1944, from carriages of 3.7 cm Pak 36s (and the nearly identical Soviet 3.7 cm PaK 158(r)) and a barrel designed originally for the IG 42 infantry support gun. As an anti-tank weapon it used a hollow charge shell with 0.5 kg (1 lb 2 oz) of explosives to penetrate up to 85 mm (3.3 in) with a velocity of 395 m/s (1,300 ft/s). The first 84 guns were delivered in June 1944. By the end of the war 1,304 guns were operational.[3]

7.5 cm Infanteriegeschütz 37
At the Panzermuseum Munster
Type	Infantry support gun
Place of origin	Nazi Germany
Service history
Used by	Nazi Germany
Production history
No. built	1,304
Specifications
Mass	510 kg (1,120 lb)
Barrel length	1.8 m (5 ft 11 in) L/22[1]
Shell	Fixed QF 75 x 89 mm R[2]
Shell weight	5.45 kg (12 lb)
Caliber	75 mm (2.95 in)
Elevation	−10° to +40°
Traverse	60°[1]
Muzzle velocity	280 m/s (920 ft/s) (common) 395 m/s (1,300 ft/s) (anti-tank)[1]
Maximum firing range	5.15 km (3.2 mi)

While the gun carriage was an old design, the gun itself was a new design created by Krupp, though the design had been shelved at the time of its conception. The gun has two distinctive features: the first is the large four-baffle muzzle brake and the second is the vertical sliding-block breech that was considered unusual for a Krupp designed gun. The breech operates in a semi-automatic fashion, in that once the gun was fired the breech block would open and eject the spent casing and remained open to allow for rapid reloading. The breech would then be closed once the next round was loaded and the gun was then ready to fire.[3]