US Cartridge, 37mm Drill, M13
The drill round is made up of inert used components from service rounds. It is used to train personnel in the handling of ammunition and in loading and unloading weapons. It may be identified by a hole drilled through the cartridge case to show that it contains no propelling charge. If an inert HE projectile is used, it will also have a hole drilled completely through it.
Nothing else to see.