I had found one of these at a rare and antique gun store recently, and I really wanted to model it. I was able to get the complete weapon modeled and textured over the course of 6 days straight working a couple of hours every evening.
The only game I remember seeing one of these was the first Call of Duty: Black Ops. The thing I thought was noteworthy about this weapon in that game was that you could select to dual wield two of these, which as impractical as that is with any weapon platform especially a shotgun, I find it even funnier seeing as how the weapon has a warning etched into the side that reads "CAUTION - DO NOT SHOOT FROM LEFT SHOULDER".
I had also seen Ian from Forgotten Weapons
cover this weapon which was also using the "Model B" which had a less than stellar performance on the shooting range. I chose to Model the HS-10A because I knew it would more challenging to design several portions, especially the integrated flashlight built into the upper enclosure.
(1) 4k texture set for the entire weapon
14k Tris (without the sling)https://www.artstation.com/artwork/XnPmPy