WWII Soviet ChK-1M 37-mm airborne anti-tank gun.
https://diqn32j8nouaz.cloudfront.net...2_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net...1_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net...e_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...906#post210309
https://www.homemadetools.net/forum/...961#post152977
https://www.homemadetools.net/forum/...434#post196803
https://www.homemadetools.net/forum/...195#post149884
https://www.homemadetools.net/forum/...355#post185209
