Leveraging Weapons Scav and Two is One, the goal for this build is maintain enough DPS on a Ranch Rifle to one tab commons and then find an RPK to demolish mutations and bosses. Ferocious common should be easy to deal with once Glass Cannon is online on a gray Ranch.
The gray Ranch that Mom comes with will stay until a better Ranch can be found, since its being used as an efficient common killing machine. The secondary primary can be really anything, but an LMG will be the best to make the most out of Patient Hunter.