PAK 40 German 75mm anti tank gun.

This gun is a beast! As you can see the muzzle blast is incredible. The WWII German PAK (PanzerAbwehrKanone) 40 was developed in early WWII but didn't see widespread production until about 1941. The gun was often used by allied forces whenever they would over run German positions which shows the effectiveness of the gun.
This gun was resurrected from an art museum where the owner had painted it pink! It was restored to working order and the federal paperwork required to build and possess this gun was obtained. It is not legal for an ordinary citizen to have a working field piece like this.