Been working up some loads in my 243. Measured the chamber and found that the the rifle likes very little or no jump onto the lands, to the point where when an unfired round is extracted there is very fine scoring on the bullet from the lands.
I understand some of the BR boys actually load onto the lands but does this not unduly increase pressures?
Accuracy is in the 0.2"s for a 3 shot group. Pull the bullet back to 10 - 20 thou jump and the groups open up to nearer the inch mark.