The second Forgotten Weapons video to feature
really big guns, the embedded flick below shows a T124E2 AT (anti-tank) gun firing. These weapons were the last of the towed American AT guns, with less than a hundred made, although the Soviet Union – and its successor the Russian Federation – continues to use towed AT guns to the present day.
The T124E2 was a towed 76mm anti-tank gun based on the M41 Walker Bulldog’s M32 (formerly T91) tank gun. With standard APC shot, it fired a 14.56 pound projectile at 3,200 ft/s, capable of penetrating 122mm of rolled homogenous armor at 30 degrees inclination at 1,000 yards. Using the more advanced HVAP shot, it fired a 7.13 pound projectile at 4,139 ft/s, capable of penetrating 208mm of RHA inclined at 30 degrees at 1,000 yards. Finally, with M331A1 HVAP-DS (discarding sabot) ammunition, it fired an 8.22 pound projectile at 4,125 ft/s. With this performance, the weapon was very capable of perforating WWII-era Russian armor beyond a kilometer, but against the newer IS-3, IS-4, T-54 and T-55 tanks, it was decidedly marginal. After the T124E2, the United States would transition to man-portable anti-tank weapons such as recoilless rifles developed at the end of the Second World War.
Two other videos exist of what I can only assume is the same T124E2 (most likely the only one in civilian hands) in an earlier stage of restoration, as it has a different gun shield:
The second video illustrates the excellent reason for the introduction of the string firing method.
Over at LovettArtillery.com, pictures of another T124E2 can be seen, this one with an intact firing lever.
AT guns were historically more dangerous to tanks than other tanks; their lower silhouette and better camouflage would make for a nasty surprise for any tanker. Though, as these videos illustrate, the great muzzle flash would certainly help give away a carefully-concealed position!