How to measure,base to ojive, and is BTO, more important than .1 of a grain for sorting bullets 108s

[Bill Norris]

Ned,
Seating depth variations aside, do u think that the differences in bullet nose length affects the bullets flight?
I soft seat my bullets long and let the gun find the seating depth. My bullets are sorted by bearing surface length. Bullet wt. I find is in direct relationship to bearing surface length.
So for me, there is no variation in seating depth. The only variable is the actual difference in the length of the bullet nose.
Thoughts?
Bob

Neck tension COULD be a variable if using light tension.

 

[Bob3700]

Since you put that way, that makes sense.
So if I went back to using this method how much longer should I set bullet depth?
How much should each bullet be moving back into the case ? If the the Jam point is say 2.400 long
Should I try and load 2.405 or 2.410 or longer?

We make a bbl stub about 1 inch long (same caliber and twist) and run the front of the reamer into the stub. This creates an example of your shoulder to throat dimensions.
I will take and place a sized case in the stub and measure from the end of the stub to the base of the case, and set my caliper to "0". Now I seat the bullet so that the caliper reads .035" longer than "0".
With the low neck tension, the bolt/lands easily seat the bullet.
The mandrel that is run into the necks before bullet seating is .0005" smaller than the bullet. So bullets are seated by the weight of the press handle. Once seated, I cannot turn a bullet in the loaded case with my fingers.
That technique will shoot as many Xs as I can hold.