OAL is not the best way to measure seating depth. I found this out using Nosler Partition 180 grain bullets. I failed to notice they have two different designs for the same bullet. OAL of these are totally different. Below are links to the two. See the difference in OAL of the bullet. I now test each new bullet seating depth in the rifle before I start loading.
http://www.midwayusa.com/product/627...tzer-box-of-50
http://www.midwayusa.com/product/212...oint-box-of-50