You are off to an excellent start in search of accurate loads! Many shooters would prefer to use only properly headstamped cases, but your plan is certainly "dooable" if you sort ammunition and cases carefully.
.30-06, .25-06, and .270 Win share the basic case and headspace gages. They differ by case neck diameter and length only. Any one can be formed into any other.
The cases should be sorted by headstamp and weight for best accuracy.
Make sure that the case necks are not too thick for chambering in your rifle. This can be done by carefull micrometer measurement, or by inserting a bullet in a fired case mouth. If it's too tight, the case necks will need reaming.