For expediency and logistical sake during World War 2, the Americans took the chassis and hull of their M5 "Stuart" Light Tank and converted it into a Self-Propelled Howitzer (SPH) mounting the useful 75mm gun in a fully-traversing, open-topped turret to create the "Howitzer Motor Carriage M8" - also known as the "M8 General Scott" or simply "M8 Scott". Production of the Scott began in September of 1942 and ran into January of 1944 to which 1,778 units were delivered. Its operational tenure went beyond that of the United States armed forces for it saw adoption by the armies of Cambodia, France, Laos, Philippines, South Vietnam, and Taiwan for use in the post-war years - namely in Southeast Asia.
The new weapon entered testing as the "T17E1 HMC" pilot vehicle. General Motors (Cadillac Division) headed the modifications of existing Stuart vehicles for this SPH role. The revised design included some notable differences from the original M5 - chiefly in a very short-barreled main gun with thick gun mantlet found in the all-new turret. The turret roof was cut away to allow for the needed working space for the gunnery crew (as well as expelling of dangerous gasses) and the turret ring diameter increased to accommodate the new turret design. The hull roof hatches for the driver and bow machine gunner of the M5 were deleted as was the bow-mounted 0.30 caliber machine gun. The lack of hull hatches meant that the entire crew of four - driver, commander, gunner and loader - was to enter and exit the vehicle through the open-air turret. Power was from the same 2 x Cadillac gasoline dual-engine arrangement seen in the M5 Stuarts while the Vertical Volute Suspension (VVS) system was also retained. Operational ranges reached 100 miles with road speeds peaking at 36 miles per hour.
The 75mm gun was either the M2 or M3 field howitzer variant whose origins were in the classic 75mm "Pack" Howitzer M1 of 1927. In its vehicle-mounted form, this weapon became the "M2" and used the breech and gun tube of the original M1. The "M3" designation simply indicated another vehicle-mounted derivative though the recoil mechanism was now part of the gun tube itself while the barrel remained the same (and interchangeable with the M2). The vehicle allowed for stowage of 46 x 75mm projectiles and defense was provided through a trainable 0.50 caliber M2 Browning heavy machine gun over the rear face of the turret tub. This was served with a 400 x 0.50 caliber ammunition stock held aboard. Armor protection ranged from 9.5mm to 44.5mm across the various facings of the vehicle.
The M8 Scott weighed 18 tons in its finalized form. Its length was just over 16 feet with a width over 7 feet and a height of nearly 9 feet.
The M8 Scott was placed into direct enemy action during 1943, primarily against the Axis forces in the Italian Campaign where it served throughout the Allied march on Rome and then Berlin. It also proved effective in the Pacific Campaign where its 75mm far-reaching, high-explosive munitions could be brought to bear on dug-in Japanese troops with some ferocity. The M8s served in this self-propelled artillery role until supplanted by converted M4 Sherman Medium Tanks which mounted the more-powerful 105mm howitzer as well as thicker armor and a more robust drivetrain. These systems arrived from 1944 onwards and spelled the end of the M8 Scott in the long term.
Post war activity found renewed life for M8 Scotts where they were used by French Army forces in attempting to contain the situation in Indochina (during the "First Indochina War" of 1946-1954). The Scott was still in play after the French left the region for they served with the South Vietnamese Army during the upcoming Vietnam War (1955-1975). Other examples fell to neighboring Laos and Cambodia.