Greg, there is no restriction on the use of bbl tuners. I had an Ezel tuner on my old Rem 540XR a few years ago and found it to be very effective. I only removed it so I could shoot that rifle in some sanctioned matches which exclude tuners. Tim's comment is valid. There are more than a few guys who cannot accurately measure their groups CTC. I have seen more than a few that were two bullets wide claiming to be in the 1's which is impossible. I used to call them out on it but there is always a pithing match when you question the integrity of any other shooter. In the end I just ignore them and use it as my own personal crucible for testing one rifle against another. I too like to shoot old vintage rifle/scope combos. They are not always the best but it is fun to take a 70 or 80 yr old rifle with an obsolete Unertl, Fecker or Balvar optic and shoot as well as my buddies fancy new rifle. I do this in our local club matches too. Won so many last winter with an 88yr old Win 52 Pre-A that half of the club now owns a 52 of some kind, lol. I have a 60 yr old Annie Super match that is hard to beat when I have ammo that agrees with it. I recently robbed the 20x Unertl off of it to mount it on a 52B to see if it would improve its performance. The rifle shot a perfect score and won its first match beating out a VuDoo, severl nice 52's, a Sako custom with Walther bbl and a few annies. Group shooting is just so hard to consistently measure and that is its biggest flaw. But it you can accept the flaws, it is still fun. I cannot recall what the attached groups measured at 50y but they were small
Irish