I would think .268 would be good or even .2675. This area is the spot that usually centers up the case in the chamber to hold the bullet in alignment with the bore.
The reamer, if your operation is set up correctly, should ream the die to the exact dimensions. You only want it to be approx. .003" under depending on your preference of sizing... .012" is to much by far. You would be better off with standard dies of the shelf.
If you are using a bushing die than you just order the size bushings needed, usually for a .268 neck it would be .262-.264 bushing depending on your neck wall thickness and tension desired. I would find -.012 to be excessive sizing on anything related to reloading.
Thanks Jerry. I always did this while fire forming brass for the new barrel and after 10 firings would check the bullet jam and record this # for the barrel. I have noticed with the .268 -270 neck dia. that with the double ogive bullets and tight neck tension you can almost shove the bullet in...
Not that long ago when testing seating depth it was recommended to start at jam and work your way in. Nowadays everyone is talking about working from the touch point and working your way out. What changed? Why?
The only way to find out is either to show up at a match and try it and see what gets decided or bring it up with your regional director and see if this can be addressed at the yearly meembership meeting to be voted on. This would seem like a subject worth discussing in light of the popularity...
You go to the first target and see who was the first one to drop an x in the order that the targets are numbered on the target sheet. If tied you go to second target and so on.