Many years ago now I had the opportunity to ask Bill Carter the owner of the Carter Country stores in the Houston area and at that time the biggest gun retailer in Texas this question. I asked what was the most common type of "Deer rifle" and round that they sold. This was way before the 6.5's were beginning to get popular and at the time the 7mm-08 was steadily gaining in popularity. He told me the most common rifle they sold by a wide margin was a bolt action in .270 Win. The next two most common rounds were the .243 and 30-06, the next tier was the .308 and 7mm Rem. Mag. He said behind these in bolt actions that they sold a good number of autoloader's in the Browning BAR and Remington 742. These were predominantly in the 30-06 and used by hunters hunting in East Texas.

Times have certainly changed.
I'd be willing to bet that now the 6.5 Creedmore and the .308 have moved up to the top sellers along with the .270
I base that on what I see coming through the hunting camps that I frequent. I also don't see many 742's and BAR'S come through as I used to.