Local consensus has it that the bullet should be seated into the bore until .040 - .060 of the base is still behind the rifling.

FWIW

The bullet should be seated into the throat until it completely seals the barrel. To see if this is true try this experiment:
Breech seat a lubed bullet to your current depth, place an already fired and primed case in the chamber. Close the action and pull the trigger. Hold your hand over the action and open it, the case should pop out with the pressure of the primer ignition. If not seat the bullet .010” deeper and repeat until you get a good seal.
Once you have a good seal you can work on your load. Every gun is different don’t assume that because 14.3 grains of 4759 worked for Bob it will work for you. Start low and work up until the groups close up.

40 Rod

Joe do not be afraid to try seating the bullet until it completly engraves all the way through the baseband. Often times it will get you where you need to go in reducing group size depending on the individual rifle. I owned one that I struggled to get to shoot and as soon as I used this approach the lights turned on and it turned out to be my best shooting rifle. When one thinks about it that is exactly what takes place when one muzzle loads a bullet to achieve best accuracy and that is what prompted me to try it as it does go against the most typical opinions of the proper seating depth. Once one reaches that majic spot a few minor adjustments will get that first cold clean barrel shot to start forming the group.

JLouis

Amen Joe long term consistency is what I look for, without it one is only fooling himself on how the rifle really shoots. I get a kick out of the fellows that luck into one good group or a 200yd. 10 Shot Target and then proudly announce to the world this how my rifle shoots! I have shot a .198 100yd. 5 shot group with my 32-40 CPA Traditional Rifle using the Flat Nose bullet and I could easly post the group for all to see and claim my rifle shoots in the 1's. When it actually will consistently shoot 5-5 shot 100yd. averages a half inch or under so it really consistently just shoots in the 5's. There are a multitude of 1/2 minute Breech Seating Schuetzen Rifles out there per the claims but over the past fifteen years of competition and the truth be told  I have personaly only seen maybe 5 and that is stretching it that can do it consistently day in and day out.

JLouis