Here's my method for a PPC and most others.
Wind flags are a must, obviously!
Start with the bullet .010 'into' the lands (done with the stripped bolt//0000 steel wool/bullet marking method). With the bullet 'into' the lands .010, you've only got one way to go...out. I start with a neck bushing .003 smaller than the neck measures over the p.r. of a seated bullet. With the powder you're testing, shoot two foulers and then:
- Go up in charge weight in .5 gr. increments, shooting 3 shot groups.
- With the charge wt. that gave the best group, load three more and repeat. Clean the gun and fire two foulers with the
same powder you're testing. Then:
- With the best charge weight, fire 3, then back the bullet up .005 at a time, shooting three shots groups at each seating depth until the groups get markedly larger.
- At the charge wt. and seating depth that shot best, load 5 and shoot. If all looks good:
- Change the neck bushing .001 at a time.
If the conditions are reasonable and you're hitting the flags consistently, 40-50 rounds should be all it takes to get there....maybe as little as 30 depending on how things develop as you test. You can always go back and tweak the seating depth .002-.003 and the charge weight by .2-.3 grs. later on.
As a final test, I shoot a 10 shot group at both 100 and 200 and evaluate where the
center of the group develops, relative to the aiming point.
Good shootin'

-Al