A friend who has recently changed from a 260 Rem in a Steyr to a 6.5 Tikka asked me to develop rounds for this new rifle. All the rifles I develop rounds for (apart from one) will shoot good groups well back from the lands. I start all development using the OCW method and with this particular rifle at 220 thou back off the land - the most promising at this 220 thou back produced a little over .6" So today having given it some thought decided to bring it much closer to the lands at 180 thou off. He came over and shot the rifle and this was the result - I always letter targets A B C etc so that the shooter has no idea of the recipe I am using so that he cannot be influenced. C shows a 4 shot (only) group of .354 edge to edge less bullet diameter of .264 - you do the math!!
So the point of this post is to say that you do not have to only consider seating the bullet 10 to 30 thou back - the average rifle has maybe 3 sweet spots and it you can find this sweet spot seating well back from the lands you will have the additional benefit of less air space in your case.
I am ashamed to say that all cases are the same make and yes, its only for deer