[Guy on a Buffalo]

Got one of these recently, 12 ga, recoil semiauto, modified choke. Trying to find some, or any info on it, but its pretty limited. Any information about it would be greatly appreciated. I know it was produced in the late 60s to the early 70s, and then it was changed to a gas recoil. I guess the other thing I am looking at is it plausible to shoot steel from, or is it better to stay safe than be sorry to just keep lead in it? Again, any info would be greatly appreciated, as I just enjoy shooting this!