The BRNO 7.92X145 Anti Tank Rifle
An experimental rifle created by Czechoslovakia in the 1930’s, the BRNO 7.92 anti tank rifle was an attempt to create an armor piercing weapon using an extremely high velocity small caliber cartridge. The cartridge was loaded with a 7.92 (8mm mauser) bullet but had a long 145mm casing which would have propelled the projectile a tremendous velocities. Though small caliber, the idea was that the high velocity projectile would pierce a tanks armor, and ricochet all throughout the cabin turning its crew into Swiss Cheese.
It was found that the round could penetrate around 11mm of armor, which could pierce most armor of the day. The rifle itself was a five shot bolt action that was fed from the top with large stripper clips. The rifle had one flaw however, it used a brass steel composite bullet that would wear out the rifle’s barrel after around 800 shots. In 1938 the Czech’s started experimenting with a removable barrel design, but the project was discontinued when Germany annexed Czechoslovakia. During World War II, armor thickness would greatly exceed 11mm, sometimes being as thick as 4 or 5 inches +. This made all anti tank rifles obsolete for armor piercing purposes.