Thread: Using comparator tool when seating projectiles.

Firstly I've trawled through this forum back to '12 looking for a definitive answer, might be there but couldn't find it. Hence the question.
I load for two rifles, a .308 and a 7x57. Both quite capable of MOA with specific loads, but not always. I have a resonable understanding of the variables involved but at the moment I'm trying to get my projectile seating sorted. I use a Forster Micrometer Bullet Seating die but find my COAL's for same projectile can vary 10 thou easily. Research indicates that's quite common and can vary 25 thou at times, making the COAL as a measurement very unreliable.
So I'll start using BTO as the measurement, when the comparator and OAL gauge arrive. I understand the comparator doesn't sit on the ogive but it will sit at the same place for every projectile of same type.

Say the BTO measurement I'm looking for is 2.752. Do I back out the seating die allowing plenty of room to seat the projectile then measure with the comparator, calculate how many thou I'm out and then screw the micrometer on the die down the correct measurement in thou and reseat? Do it for every cartridge?

That was suggested some years ago by a member.A bloke, Zimmer, said that would be very tedious.

So what is the correct method?

Both rifles are hunting rifles but I can't think of a good reason why they shouldn't shoot to their full potential. One in particular will be used out to 400 and beyond. Same rifle will be used in NZDA comp shooting, but nothing serious.

Cheers RM77