unlucky or what?

I CAN NOT find this rifle ANYWHERE. i’m about 60 or so days in and i started in the forlorn muskeg and explored all that. then moved on to mystery lake and set up in the cabin and explored all of mystery lake. i’ve explored all of the ravine, coastal highway, crumbling highway, and the desolation point and have explored most of mountain town as well since then. i haven’t found this rifle anywhere and i have like 43 bullets for it lol. Should i go back and explore the broken railroad and hushed river valley or go up to ash canyon?