Great info! There is some thought that tune for a given bullet and powder may be velocity specific. The reason that I mention this is that if it is the case, and I think that generally it is, if you make a change in something that changes velocity, that you might want to adjust your powder charge to put it back on the same velocity, assuming that you have tuned succeessfully with one set of variables. In my experience, if you first neck size with a collet die, and then use a body die, set for proper shoulder bump, with unturned necks, you will probably have the most consistent neck tension and runout. Just remember that in order to adjust neck tension, you will have to either modify you mandrel or buy an additional one. As far as annealing goes, I think that you will find that for starters, that you may want to stick with sorting by seating force. IMO it is easy to go backwards if necks are made too soft. Also, if you do, be sure to set your FL or body die from scratch, as the softened brass will take a different setting. Another opinion, you need to put out some sticks with surveyors' tape tied to their tops (down to the ground) to see what the wind is doing. Without them you will make the mistake of thinking that some difference in groups is the load, when it is not. On the trigger, I would see if I could find a used old style Remington, and do the spring kit for it. You will need the safety for it. They are different. You might be able to get some 175 gr SMKs to make 1,000. Have you played with primers? I would do my own testing as to how many rounds it takes to settle down your barrel after cleaning. They can vary, depending on how rough they are. One time I met a fellow with a stainless Ruger .270 that was cleaning way too often, and although he was a good shooter, and a meticulous reloader, he had been chasing his tail for 6 mos trying to get under an inch and a half with that rifle. After talking with him for a while, to learn what he had been shooting. I advised him to stop cleaning so often, and after seven or eight shots the barrel settled down. It turns out that that had been his problem all along. His load was fine. How are you holding the rifle, and pulling the trigger? The reason that I ask is that a lot of shooters have issues here because they try to hold the rifle too lightly, and because they do not slowly add pressure to the trigger, while holding point of aim, and let the rifle surprise them as to exactly when it is going off. I also find that follow through is a major issue. You shoud react like as sack of grain when the rifle goes off, only snowing the body movement that recoil produces, no reaction, or bringing your head up quickly. BTW I did not mean to discourage your testing. I have always enjoyed doing that myself. Good luck, and report back on your results.
Boyd