I have a deep love for 270 Winchester after almost 40 years of shooting and hunting with it, but if I was forced to only be able to hunt with one cartridge in TX and OK, I’d more than likely choose 308 for a couple reasons. The main one being my combo gun is chambered in 308, and another is that I already have proven loads for 110 gr, 165 gr, and 180 grain bullets that should cover about anything I would want to hunt with a centerfire rifle.