8-inch Gun M1

The 8 inch Gun M-1 was a 203 mm towed heavy gun developed in the United States. It was used by the US Army and the British Army in World War II.

Country Name Origin Year
United States of America 1944
Country Name Operational Year Retirement Year
United Kingdom - UK (Great Britain) View
United States of America View

Serious development began in June 1940 of an 8-inch (203 mm) gun that would have a range of 33,500 yards (30,600 m), a road speed of 25 mph (40 km/h), be transported in 2 loads weighing no more than 44,000 lb (20,000 kg) and be suitable for rail movement. Use of the carriage of the 240 mm howitzer M1 eased development, but the gun was very troublesome and wasn't standardized until January 1944. The main problems were excessive bore wear and poor accuracy, but it was felt that nothing better could be produced in a timely manner. Thus it entered production at a low rate and in small numbers.

Like the 240 mm howitzer, it was mounted on a stretched Heavy Tank T26E3 chassis that had an extra bogie wheel per side as the 8in Gun Motor Carriage T93, but the war ended before they could be used and were later scrapped.

Type Heavy gun
Place of origin United States
Service history
Used by United States
United Kingdom
Wars World War II
Production history
Designed 1940–1944
Produced 1944–?
Weight Combat: 69,300 lb (31,400 kg)
Barrel length 33 ft 4 in (10.16 m) L/50
Shell separate-loading, bag charge
Caliber 203 mm (8.0 in)
Breech interrupted screw
Recoil hydropneumatic
Carriage split trail
Elevation +10° to +50°
Traverse 30° (initially), post-war 40°
Muzzle velocity 2,840 ft/s (870 m/s)
Effective firing range 12.5 mi (20.1 km) (minimum)
Maximum firing range 20.24 mi (32.57 km)

End notes