Anti-Tank Rifle ProblemThe British began World War Two with the Boys antitank rifle, but like all antitank rifles it rather quickly became obsolete. The replacement for it was adopted in 1942 as the PIAT – Projector, Infantry, Anti-Tank. This was a unique sort of weapon which fired a 3 pound (~1.35kg) hollow charge projectile using a combination of a massive spring and a firing charge much like a rifle grenade blank cartridge – a spigot mortar, really. The large (3.25″, 83mm) projectile was able to defeat almost any tank that would be developed during the war, as it could burn through 3-4 inches of hardened armor. However, it had a terrifyingly short effective range – 110 yards on paper and more like 50 yards in practice.
The PIAT would recock itself upon firing, but the initial cocking was something like a crossbow, requiring the shooter to brace their feet on the buttplate and pull the body of the weapon upwards, compressing the 200 pound (90kg) mainspring. When fired, the weapon has a pretty harsh recoil, although it did not have any flash or backblast like the American Bazooka did. By the end of the war more 115,000 PIATs had been made, and they would serve the British military into the 1950s, when they were replaced with more traditional rocket launchers
Credit to : Forgotten Weapons