For about 20 years, the only "deer" rifle I had was a M88 Win in .308. So..most of my firearm kills wwere with that old heirloom rifle. Then I got the bowhunting bug, and moved to an area that gave opportunity for plenty of same. My rifle kills are not as high as they might be otherwise.
As bamaboy came up, and I started to slow down a tad, I've come back to gun hunting a little bit anyhow.
I retired the M88, and have played the field since. I'm prone to light, short rifles, and a .44 Ruger and a 7.26x39 Mini and M77 have been carried plenty. I still hunt .308 in a Savage Scout. But.... my current favorite caliber may well be .243. Fast, flat and more than enough for whitetails with the right placement and slug.