I owned 3 and currently have 2 a 20guage and 12 guage. Awesome gun, Semi-auto shotgun was getting very popular in the 70s and early 80s. S&W and Mossberg do not have semi-auto of their own and they contracted a Japanese company to manuafacture for them. You could also get parts for them under the name Mossberg 1000, the same gun with different name. I guessed it is like "Chevy Luv and the Isuzu pickup" during the 80s.
It is gas operated, which mean you'll have to clean it more often then the spring type. The action is so smooth as well compared to my Browning A5, after all day for doves my poor shoulder is not bruised up like my A5.
hopes this help, somebody correct me if I am wrong..
Al