Why don't we have anti tank rifles anymore? - Quora
The Anti-Tank Rifles of World War II | SOFREP
Kurchevsky recoilless anti-tank rifle (USSR) - Modern Firearms
Experimental PTR RES anti tank gun from 1942. 20 mm bullet was based on 45 mm casing, that gave it velocity of around 1300 m/s with roughly 60 mm of penetration at