A while back, a famous shooter stated that he had concluded that threading the end of a barrel was a sure fire killer of accuracy. After he published his so called "test" to prove this, it was obvious that some outside source, (perhaps a bottle of Jack Daniels), was involved in the procedure.
The tuner I use has 2 inches of .900 36 tpi on the barrel,the tuner has a corresponding thread. The split alllows two 6-32 pinch bolts to lock the tuner. It also incorporates a "dampenning" feature, which I believe widens the tune window. The design is also very "user friendly" at the line, no small matter if you decide adjustments are called for.
One reason I favor the very fine thread is that it is easy to lock the tuner with very little pressure, and you can fine adjust it, 1/4 turn is only about .007 inch advance.
One of the problems we have with this subject is there are shooters who interject opinions into the discussion who know very little about 100-200 yard Benchrest, and do not test their ideas in the only lab that counts, The Competitive Arena.
Personally, I have no stake in what shooters do. While I have built a few tuners for close friends, I have no desire to produce them. I just get an idea, build something, try it in Competition, and report to this Forum what I have found out. Shooters can sift through all of the claims and figure out what works.........jackie