I use the Frankfort Arsenal tool method which produces consistent ogive contact with the lands.
However, due to variations in bullet ogives, operator consistency in using the tool and caliper, I have never been able get a group of measurements that are identical. So, my approach is to measure 5 bullet per lot and use the average unless I encounter an extreme outliner in which case I reject.
Since I never seat bullets into or touching the lands, this is no big deal. I typically seat about .010 to 020" off the lands taking into account magazine fit. My goal is to assure that I do not touch or jam into the lands thus this procedure works quite well for my purposes.
With that said, seating depth can make a difference if you are seeking the best groups for your rifle. At least this has been my experience. But in my experience, the improvement, while measurable on target, pales in comparison to the bullet and powder selected.
However, due to variations in bullet ogives, operator consistency in using the tool and caliper, I have never been able get a group of measurements that are identical. So, my approach is to measure 5 bullet per lot and use the average unless I encounter an extreme outliner in which case I reject.
Since I never seat bullets into or touching the lands, this is no big deal. I typically seat about .010 to 020" off the lands taking into account magazine fit. My goal is to assure that I do not touch or jam into the lands thus this procedure works quite well for my purposes.
With that said, seating depth can make a difference if you are seeking the best groups for your rifle. At least this has been my experience. But in my experience, the improvement, while measurable on target, pales in comparison to the bullet and powder selected.










