The reason that I ask this question is that when our club rifle is in maximum use I will give my rifle to the shooter who is waiting, (and they are often not that experienced) who then proceed to shoot 56's plus with factory HBC's.
With my chamber it means that the HBC are jumping 80 thou., and yet they still waterline the centre.
I also shoot my hand-loads with a 30 thou jump with no problems.

When I neglected to keep up the checking of throat erosion in my son's Angel I found out that it was jumping 55 thou with no loss of consistency in elevation. I reset to seat at 30 thou but it is probably back to 50+ again. That barrel has now had over 5500 rounds through it and is still humming.

The club Omark will waterline the target consistently and I calculate that it is also jumping 60+thou with factory HBC's.
A lot of elevation problems (discounting the shooter) are caused by not aligning all components during the reloading, and that is from the first stage of resizing, whether full, partial or neck. Whatever you do from that point on is a waste of time if you don't get that part right.
Another item to take into account is how quickly does your barrel foul, and, does it clean up properly to start with.


Ray.