It makes a difference with different bullets too. I mainly use 130 Nos Bt in my 270WSM (A-bolt also) and they are all but touching the lands and shoot under an inch and still fit in the clip.

I also have tried the 130grn Barnes XLC bullets and they like to be away from the lands. I cant remember the exact measurements.

Also if you havea pointed bullet like a BT it will be alot longercompared to a HP or SoftPt of the same weight. Soa Soft or Hollow ptcan actually be seated out further but still fit in the clipand be closer to the lands because the fatter part of the bullet that actually hits the lands is closer to the front of the bullet compared to a BT. Thats a little confusing so I hope you understand what I meant.

You know if this was all real easy it wouldnt be much fun.