The biggest advantage of the 6 mm rem over the .25-06 is it's ability to shoot 55 grain bullets and give very serious competition to the .22-250. It can also kill deer at extended ranges with 100 grain bullets. Go 1-9" twist or faster....you will still have a few .30-06 rifles for other larger game so go the distance and rebarrel toi the 6mm Rem....it's a lot more than anyone thinks.
A 75 from a 25-06 is no slouch when compared to a 55 from a 6mm.
If that competition is colony varmint shooting neither gives the 22-250 a run for its money. Both simply have way too much horse power for prarie dogs and the like.
I have a 25-06AI and typically fire form cases by shooting prarie dogs. After a a dozen or so shots it becomes apparent it's way too much.
