I've been reloading the '06 since 1950.
I have found no problems whatsoever with neck-sizing only. If scrounged brass will chamber in my rifle, I don't bother to full-length resize. I do a full-length resize only if I find brass from somebody's rifle which has a larger chamber than mine...
You can neck-size with an FL die. Just don't screw the die down into the press all the way. Set it where the neck is sized for roughly 2/3 to 3/4 of its length.
After you've reloaded the same brass for a dozen or more times, you can then consider annealing (softening) the brass; it work-hardens with the resizing. But come back after you've done some organizing, loading, and shooting.
, Art