I'm reloading for my rifles, at this point, my main focus is my 7mm Mag BAR. I've got the Hornady LnL OAL gauge and Hornady Bullet Comparator. The bullet I'm using is a 150gn Nosler E-Tip. I measured the space to the rifling lands, and have my seating die set to as close to 2.7715" (measured using the Comparator, so the true OAL is longer) as I can get it. This places the bullet .075" off the rifling (using the comparator, the bullet is on the rifling @ 2.8465"). Nosler says the E-Tip should be .050-.100 off the lands for "Optimum Accuracy". Two main questions; one, using the comparator with the 7-28 collet takes the measurement at a much different point then where the RCBS seating die contacts the bullet. The 4-25 collet is MUCH closer to the same place the seating die contacts it. Is this likely to be an issue with reliable seating? Should I instead be using the 4-25 collet for measuring the 7mm? The other question is the seating depth seems to fluctuate as much as .0085. Am I worrying too much about such a relatively small variation? Is it enough to throw off accuracy? FWIW, loaded like above, I've gotten roughly 1/4" grouping @ 100yd with my BAR MkII, and that 1/4" could be from the shooter (me), not the rifle or bullet.