Forgotten Weapons: The Nazis’ Desperate Attempts to Curve a Bullet (VIDEO)
The Krummlauf is a perfect example of Germany’s late-war obsession with impractical secret weapons to turn the tide of the World War II—which actually had the effect of diverting critical resources to outlandish ends. It is a curved barrel device that was clamped onto the end of an MP-44 rifle to allow soldiers to shoot over obstacles without exposing themselves to return fire. It might be an interesting idea, but it’s surely not going to change the outcome of the Battle of Berlin.
Actually, development of the Krummlauf began in 1943, when early testing was done to attached a curved 20mm barrel to an 8mm rifle. The idea was to use the curved 20mm section as a sort of trough to redirect the bullets. It was assumed that a curved barrel that was actually the same diameter as the bullet would cause too much stress and friction to work—but that notion was disproven in later tests. It turned out that a standard diameter barrel actually worked much better.
Two different versions of the Krummlauf were made. One had a 30° bend to the barrel, and was intended for infantry use. The other had a much more severe 90° bend, and was intended for mounting in armored vehicles. The vehicle model was designed so the rifle could sit in a vertical position, which would take up the minimum amount of space. The curved barrel went through a port in the vehicle’s armor and could be swiveled around. Reportedly it was first intended for use in the Elefant tank destroyer, which had no mounted machine guns. The Krummlauf would give the crew a way to shoot at enemy soldiers trying to approach the vehicle with explosives or incendiaries. An example mount and vehicular Krummlauf survives today in the Koblenz museum in Germany.
The infantry model is more commonly seen today. Its barrel was a total of 14 inches long, with a 4 inch straight barrel, then a 5.5 inch curved section, and then another 4.5 inches of straight barrel. It included a large mirror to allow a soldier using it to see where the gun was pointing while maintaining a standard hold and cheek weld. A front sight was mounted on the end of the Krummlauf, and a rear sight was located just behind the mirror.
U.S. military testing at the Aberdeen Proving Ground after the war showed that bullets usually would break in half at the cannelure when fired through the device, making it useless for anything but very close ranges—although that was not really a problem as very close ranges were the intended use of the weapon in the first place. A series of vent holes were drilled into he initial straight section of the barrel to relieve some of the gas pressure as the bullet entered the curved section, although this did not prevent the device from having a service life of only a few hundred rounds.