Now look back at the base of the machine gun, at the round metal endplate. Midway between the handgrips, on the top of the machine gun, you will spot an L-shaped metal strip. At the top of that strip, below, you’ll see someone has drilled a small hole into its top. That hole is threaded. We’ve highlighted it in red to help it stand out.
What is its purpose? Only in the digital age would you guess it. The hole has been tapped to receive a standard tripod mount for a digital camera, affixed so that the lens points down the barrel’s length.