I tend to stick with one rifle for a long time. Started out with a 30-06, then had two .308's, these have harvested the vast majority of my Deer. I've occasionally shot one with my 7X57 (over under, 7X57, 12 gauge) and occasionally with my 35 Rem.

I have .308 ballistics imprinted in my brain and know within a minute of angle what it is going to do out to around 400 yards. Half a minute of angle out to around two hundred. If it ain't broke don't fix it.