The Walther A115 was one of the semiauto rifles developed in pre-WWII Germany. Apparently only three were made, and it uses a neat combination of sheet metal construction with a rotating bolt and annular gas piston like the later G41 rifles. This particular example was examined by Aberdeen Proving Ground in 1955 (you can find their photos of it around) before escaping into the private market.
At Forgotten Weapons I think the most interesting guns out there are the most obscure ones. I try to search out experimental and prototype weapons and show you how they work, in addition to more conventional guns that you may not have heard of before. You’re much more likely to find a video on the Cei Rigotti or Webley-Fosbery here than an AR or Glock. So, do you want to learn about something new today? Then stick around!