In my part of the world---and I am NOT a travelling hunter, a .30-06 would be more than sufficient but certainly not a mistake. Actually I think anything .257" and up based on the '06 case would do, all the way up to .35 Whelen. I could get by on a .25-06, but I have an attachment to the .280 Remington that just won't quit and that's probably what I'd choose assuming that components would always be available.
If component AND ammo availability were to become a problem, I'd probably opt for .308 Winchester with a bit of reluctance...but I'm sure I'd get by.
If I could only have one rifle but it was guaranteed that components would never be an issue I'd be tempted by .264 Win Mag also. There's just nothing in Texas it can't handle.
I would sure hate to have to make the choice.
