Based on your pictures of your three-shot groups, I would bet that if you shot each of those loads as ten-shot groups they would all be pretty much identical. I'd say pick one that has the velocity you want and run with it. Or, pick the 45 grain load to make your powder last longer, if you're hurting for powder. That's a round about way of saying "nice groups" and, "pick one". Personally, in my opinion, based on how good your groups are in the photo, seating depth is probably not going to matter much. It looks like you are there. Like I said, that's just my opinion.
