So I scratched my head for quite a while on this one. I measured the Base to Lands on my 6.5x284 with a few different bullets, 140 ELD-M, 143 ELD-X, and 147 ELD-Ms. Ended up mostly shooting the 140 ELDMs with a load of 52.0 gr H4831 @ 2910 fps 0.02" off the lands. Then recently I noticed I'm getting pressure signs with the exact same load when I wasn't getting pressure signs a full grain higher doing load development. I re-checked the Base to Lands measurement and I was now somehow seating my bullets into the lands ~ .015" with the exact same COAL that was 0.02" off the lands during development! The only thing that changed was the Lot# of bullets. My drops are still on out to 900 yards, but I suspect the initial pressure of jamming the bullet is pushing me over, I seated some deeper to test this week when it stops snowing. Yesterday I remeasured the Base to Lands with all the same bullets, including a 3rd lot # of ELD-Ms and they were .035" off my first Lot. I still have the original 143 ELD-X & 147-M's I measured and they were identical to the first measurement. However, measuring the base to lands of 3 different lots of 140-M bullets I found a difference of about 40 thousandths between lots! Has anyone else recorded similar variations?