Before the United States had battle experience against heavily armored German tanks, the development of a weapon superior to the 75 mm gun was anticipated.

The original Ordnance Department specifications of 11 September 1941 for the M4 tank allowed for the mounting of numerous weapons including the 3 inch gun.

[6] The first specimens of the weapon that was to become the 76 mm Gun M1 were being evaluated in August 1942 while the U.S. did not enter the ground war in the European-African-Middle Eastern region until Operation Torch in November 1942.

[6] Another T1 test gun was produced with the barrel shortened to 52 calibers and a counterweight added to the breech guard to improve balance.

An 800 lb (360 kg) storage box was added to the turret rear to improve balance,[1] with evaluations held in early 1943 and the final report tendered in April 1943.

[13] A more satisfactory mounting was found in August 1943 by utilizing the turret design of the T23 tank on the M4 chassis to carry the 76 mm gun.

[14] The 76 mm M1A1 version of the gun was then created, having a longer recoil surface to also help with balance by permitting the placement of the trunnions further to the front.

[14] By August 1943, the M4 tank armed with the 76 mm gun in the modified T23 turret was finally ready for production.

Summed up, the 76 mm offered about 1 inch (25 millimetres) of added armor penetrating power for a loss of some high explosive firepower.

The Ordnance Department initially reduced the amount of smoke by using a long primer that gave a more complete burn of the propellant before it exited the barrel.

[19] Muzzle brakes, that redirected the blast left and right, were tested in January 1944 and authorized in February 1944, with production starting in June 1944.

[21] Far more high explosive ammunition was used by tankers than armor piercing types, the proportions being about 70% HE, 20% AP and 10% smoke overall,[22] The ratio could vary by unit: From 3 August – 31 December 1944 the 13th Tank Battalion fired 55 rounds of M62 APC-T armor piercing versus 19,634 rounds of M42 high explosive.

[26] It was thought that the longer and heavier 76 mm might impede handling inside the tank's turret, slowing the rate of fire.

[32] The moderate performance of the 76 mm gun by 1944 standards was one of three reasons the plans for M18 production were cut from 8,986 to 2,507, of which 650 were converted to unarmed utility vehicles.

Plans were made by field units to directly replace the 75s on some tanks using a weight welded to the turret rear to balance it.

[42] Another issue surfaces on detailed analysis: a change induced by the problem with the M18 turret and the weight of the original 76/57 development gun.

The 76 mm M93 High-Velocity, Armor-Piercing Tracer (HVAP-T) was a large improvement being an Armor Piercing Composite Rigid shot, where the full bore, lightweight outer shell contained a slug of tungsten alloy.

The American APCR data seems to indicate that US designs were superior to German and their Soviet copies in retaining their velocity to longer ranges.

The US Army did not adopt the APDS shot until the middle 1950s as the British designs were less accurate, having significant problems of dispersion from point of aim.

Although only slightly longer at 55 calibers, their Ordnance QF 17 pounder (76.2 mm) anti-tank gun had a much larger 76.2×583mmR cartridge case, which used about 5.5 lb (2.5 kg) more propellant.

The 76 mm gunned Shermans supplied to the British were only used in Italy or by the Polish 1st Armoured Division in north-west Europe.

These 76 mm-armed Shermans served well in the Korean War and, having better crew training and gun optics, had little problem piercing the armor of North Korean-manned T-34/85 tanks when firing HVAP rounds, which were amply supplied to units.

[6][43][45] France delivered 76mm-gunned Sherman tanks to Israel which used them in Operation Kadesh against Egypt in 1956 and in the 1967 Six day war, particularly in the conquest of Jerusalem.

[49] The substitute standard M79 Armor Piercing solid monobloc shot had no filler, windscreen, or penetrating cap.

Smoke Shell contained a filler of H.C.[49] Based on a British design, it was intended to provide a slow-release "curtain" of smoke versus the exploding white phosphorus shell available to the 75-mm and other cannon originally designed for artillery spotting but which could also cause damaging burns.