I use the Mossberg 5oo, and I like it just fine, but a one handed gun it is not. You will have to go semi-auto, or single shot. You will not be able to cock it between shots.
Military guns would not have the barrel requirements of civilian weapons (minimum barrel length) and leverage would work hard against you.
A one handed shotgun would need to strap to, or sleeve your forearm for support and recoil.
One handed shotguns are available now in the form of the revolver "the Judge" and it's various copies.(.410ga)
A sleeved, shotgun with a very short barrel and semi-auto, aimed like a fist, would do very well for self defense, but would not be usable for hunting. except at extremely close range.
A long barreled one would require a rest or tripod mount. (due to leverage and recoil)
The "Judge" is available as a pistol, and as the "Circuit Judge" in a rifle/shotgun version
Good luck with your project, but I think you will have to refine the use of your weapon.
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.