what I am looking for is a rifle to keep in the truck with me as I travel for when I need it. might be to put down an animal or smoke a coyote or get my beloved behind out of a bad place. I'm thinking 308, mostly because I like overkill and availability of ammo. maybe 5.56 would be good enough, you guys with more experience than me can tell me. I'm thinking semi-auto as might need to shoot fast. I'm thinking shorter barrel like 18". and never know might get to shoot it some distance when have down time with jobs and can find a place. recommendations on a scope would be good also. So let's let all that pent up wisdom in here out and school me. thanks in advance.