Krummlauf

The curved barrel included a periscope sighting device for shooting around corners from a safe position.

Another problem besides the short life-span was that the bending caused the bullets to shatter and exit the barrel in multiple fragments, producing an unintended shotgun effect.

As a result, weapons designers experimented with small vent holes drilled into the Krummlauf's barrel in order to reduce pressure and recoil, allowing the discharged bullets' built-up gases to be released to slow the bullet's velocity as it turned to exit the barrel.

A triangular shield was also added to prevent venting gasses from clouding the mirror and optics.

The Krummlauf in a Maschinenpistole Vorsatz (P) mount was developed as an alternative close defence weapon for tank destroyers.