Chang Jiang is a Chinese company that manufactured motorcycles (among other things) from the 1950’s through the 1970’s. Exact dates are hard to come by, but that is not really relevant. The CJ750 was their primary model. It was based on the 1956 Soviet IMZ M-72, which was in turn based upon the 1938 German BMW R71.
The ad for this bike has precious little information, but it is listed as a 1979, and has been through a major rebuild. I’m sure a check with the seller would answer some questions as to the exact model, whether it has upgraded 12V electronics, reverse gear, etc. The ad does say it comes “loaded” with accessories like sidecar cover, spare, etc. I see the gun mount, but no mention of a 50 cal…….
If you like being the center of attention while picking up groceries, dropping kids at soccer, etc, this could be for you! Find out more by contacting the seller through Craigslist. The bike is located just south of Atlanta, in Peachtree City, GA and listed for $6,500.