It's all about COAL.
243AI,by a mile...............
+1
This short comment probably went over the heads of most, but being able to "kiss" the lands and use the magazine box are critical for extreme accuracy.
If you have a short action, then the 243 AI is the way to go. If you have a long action, then the 6AI is the way to go.
I have always used Rem 7/08 brass for the 243 AI, turn the necks at 7mm, then use the 7mm dia to create a false shoulder where you set the headspace for your 243 AI, never loose a case.
Just in case you think that Rem brass will not shoot tiny groups, you badly mistaken.
