I set an initial zero, then removed the barrel, replaced it, fired 3 rounds, removed the barrel, replaced it, fired 3 rounds, etc... for 15 rounds with the same POA for every shot. The total group of smaller 3-round groups was about .6 mils wide, and round. That particular rifle typically shoots .15-.2 mils for a 5-shot group.
So long story short, the center of my group is likely to move up to 0.2 mils from where it was in any given direction. I did not see a directional trend.
I have since swapped back and forth between the shouldered and lock-nut barrels a couple times, and while I haven't kept good notes, based on my zero-stop setting, that typical trend is holding true with the shouldered barrel. ( I had 1.0 mils "down" in reserve to hit the zero stop, for fudge factor, and keep between .8-1.3 or so every time I re-zero with the shouldered barrel).
Witness marks are sharpie dots on the stock showline. Calibers are 6.5 SAUM for the shouldered barrel, .260 rem for the savage prefit.
So long story short, the center of my group is likely to move up to 0.2 mils from where it was in any given direction. I did not see a directional trend.
I have since swapped back and forth between the shouldered and lock-nut barrels a couple times, and while I haven't kept good notes, based on my zero-stop setting, that typical trend is holding true with the shouldered barrel. ( I had 1.0 mils "down" in reserve to hit the zero stop, for fudge factor, and keep between .8-1.3 or so every time I re-zero with the shouldered barrel).
Witness marks are sharpie dots on the stock showline. Calibers are 6.5 SAUM for the shouldered barrel, .260 rem for the savage prefit.
