Cabela's Survival: Shadows of Katmai

You get the weapons in the following order: Handgun, Bolt-Action Rifle, Semi Auto Rifle and, lastly, the shotgun. As long as you exclusively use each new gun as you unlock them, you should have no problem getting this trophy by the story’s end. That said, if you get impatient and want this trophy right away (like me), then you can actually reload checkpoints to farm the kills whenever you find a good spot.