Gentlmen, there are quite a few technical reasons that ammo for semi and full auto ammunition should be held to certain tolerances!
That understood there is no reason you can't
do a perfect job for your Garrand and your Model 70 with the same set of dies.
You just can't set the dies to the same place for both rifles!
Get a headspace gauge for the autoloader and learn how to use it to make safe ammo. Neck size for the bolt gun, I do, and watch out for case wear on all.
I'm with Art, "If it ain't broke don't fix it" but slightly over headspaced ammo in a semi might get it and you "broke" quicker than you want.
Good "and safe" Shooting