If you're trying to get very consistent seating depth, it is convenient to know which brands of bullets have the most consistent length. Here are standard deviations from samples of several brands of 30 cal bullets. Those with smaller standard deviations are more consistent.

Hornady 130 SP .0029"
Hornady 165 BTSP .0029"
Nosler 180 Partition .0029"
Sierra 180 SPBT .0072"
Hornady 180 SPBT .0045"
Speer 180 HotCor .0013"

You can figure that about 95% of cases will fall within two standard deviations of the mean.

More important is a consistent ogive reading tahter than OAL as tip deformation can affect that,

Denton __

Good numbers (as usual). My results (different bullets) show similar disparities. Which is why....

D B Bill __

....I use the Stoney Point gages and devices to measure to the ogive. However, a word of caution is offered. Like everything else in our handloading world, even the ogives of the same bullet types from the same manufacturers are inconsistent. Unless a "Lot No." is present on the manufacturer's container, the ogive shape may not be the same from container to container, or even within the same container.

My practice has been, if the use of the bullet demands, to sort out bullets by weight and by ogival dimension. But then, most of my shooting involves controlled experiments where such data is mandatory.

Good shooting.

Robert