Encounters with heavy German tanks like Panther and Tiger settled the arguments when the European Theater requested that production of 75mm and 76mm gun tanks be halted in favor of 90mm gun and 105mm howitzer tanks.(36) It should be noted that the problems with the 76mm and 3" guns did not necessarily involve the weapons themselves: the noses of US armor-piercing ammunition of the time turned out to be excessively soft. These ammunition deficiencies proved that Ordnance tests claiming the 76mm gun could penetrate a Tiger I's upper front hull to 2000yd (1800m) were sadly incorrect.

The final death knell of the Tank Destroyers was also sounded when the Theater General Board in Europe, after studying the after-action reports of the forty-nine tank destroyer battalions that fought there, recommended that the Armored Force itself accept the more successful components of the Tank Destroyer doctrine and that "the tank destroyers as a separate force be discontinued."(54) The Tank Destroyers were quickly disbanded

The Board also recommended that an armored regiment be assigned to each infantry division, while the infantry division's regimental antitank companies be deleted.(56) By implicitly stating that the best antitank weapon was another tank, this recommendation directly defied the earlier doctrine that tanks were not to fight tanks.