Tad, with all due respect, rimfire shooters are the worst about over complicating tuners. Probably because of poor ammo quality/choices, magnified variables in said ammo and condition related changes such as wind drift, and a plethora of what I believe to be, bad info out there.
I chuckle when I hear people say that tuners work differently on rimfire. Two things change...in bore time and amplitude of vibration. Otherwise, the gun has no idea whether the cartridge has it's primer around the rim or in its center. In a nutshell, everything is slower and the tuner needs larger adjutments on a rimfire. By larger, I mean move the tuner no more than TWO marks at a time on a rimfire, vs 1 on a cf. Also, the range of tuner adjustment, between in tune and out of tune is about double. So, in a typical short range cf br rifle, there are almost always 4-5 marks between in tune and out, with my tuner. In rf, that's about 8-10 marks. Still, a very small and manageable window to work within without getting lost and confused with random tuner changes all over the place.
Without going into great detail as to why, I recommend starting with my tuner 1/2-1 full turn out from bottom.
Oh yes any idea that can be conceived has been around the rimfire tuner. Some make some theoretical since, most others not really.
So if it is 4-5 clicks between in and out of tune with your tuner, how are you deciding that for instance setting 20 is better than 24 or 25 or worse than setting 15? I don't know how you tuner is numbered or set up to be able to see where you are at on it so I just picked some easy numbers there to use.
I ask this because with a harrell on my rimfire rifle, I can pretty well like clock work go forward 17 clicks, or backward 17 all the way to the ends of the threads and the rifle still shoot pretty well. Just none of the other places shoot quite as well as where it is right now. I have burned way more good ammo than I want to admit making sure that this is the best setting on this thing and not just another place that shoots so-so.
Do you all see with your centerfires that there ends up being a 'best adjustment range' between a certain 4-5 clicks or does basically any 4-5 click range of the tuner all pretty well shoot about the same? I know that almost starts to get ino your conversation with Marty about getting it to shoot vs getting it in tune and I am trying to stay away from that in lieu of seeing more info on the subject.
Tad