My 110lb wives Troy "other", chambered in 5.56. Thank God its legal where we are at, as its ability to be made slightly smaller in length, allows her a safer, and more enjoyable experience ripping thousands of rounds at unsuspecting pine trees, and beer cans.
I think its an old school Mossberg 500, but i could be wrong. Mossberg has been has been pumping these out for decades, so 30 to 40 plus years is not out of the ordinary. I have a Mossberg 500 myself, and even though my Mossberg has some, er um ahem lets say "modifications", it still looks similar to this.
I have the same one but it is an ATP with an unrifled barrel. What I was told, the model with the P after the AT was a police model. The police used it many years ago for riot control. They would aim the barrel at the ground in front of the crowd and the buckshot would ricochet into the crowd instead of directly shooting people and risk killing them.