Thread: Using comparator tool when seating projectiles.

Personally i wouldnt worry about trying to measure to the lands with a Hornady OAL tool, I have always just loaded a projectile long in an empty case, tried it in the rifle with a bit of vivid on the ogive and just progressively seated it deeper in the case and kept trying it in the rifle till the bolt finally closes nicely & faint mark of rifling on the vivid. Measured that BTO then knocked it back another 10 thou and started from there. At the end of the day you had a load that was working well in that gun most of the time with the issue being inconsistent seating depth due to measuring COAL rather than BTO. I would load a round at your original powder charge and COAL, use Hornady Item #B234 Comparator set to measure what that ends up being as a BTO measurement. Once you have that measurement, Load up a seating depth ladder close to what that measurement is, for instance if it measures 2.610 BTO, i would load a ladder 3 rounds at each depth from 2.619 down to 2.601 in 3 thou increments & go shoot them, Giving you a 18 thou spread in seating depth around the area that worked for you before. Surely somewhere in there you will find what works.