Stick with 25-06 or buy another 270 or even a 30-06. I noticed that our Wal-Mart has more 7mm Mag ammo than 270, 30-06, 243, 308, 300 WM or any other large caliber. I was pretty surprised at that.
I would pick a caliber and then buy a few boxes or even a case online, if you cannot find it...