Most countries still had anti-tank rifles in their military inventory at the beginning of WWII – the Solothurn S18-100, the Lahti L39, the Boys AT Rifle, the PTRD and PTRS, and so on. For Germany, this role was fulfilled by the Panzerbüchse 39, a single-shot falling block rifle firing a high velocity 8mm AP cartridge. It was nominally effective in the opening campaigns of the war, but was quickly rendered obsolete as Allied armor improved. German planners has a huge number (25,000) of these on hand for the invasion of Russia, where they expected Russian armor to be vulnerable to them – which was not the case. Most were subsequently converted into Granatbüchse 39 AT grenade launchers, which were then used until the end of the war. Finding one of these still in its rifle configuration is pretty rare today!