Originally Posted by AZShooter
I like to start with a seating depth and work up powder first because the seating depth selection will often work without any changes. The Berger hybrids are really good in that regard.
But accubonds, ballistic tips and other brands have not required seating depth changes.
Not to start an argument but not sure seating deeper would necessarily raise pressures. Sure the powder is put into a smaller space but the bullet is experiencing a some freebore. This could make for an interesting discussion apart from this thread. I'd would chance a guess that it would depend and the pressures could go up or down based on individual rifle/brass/bullet/powder combos.
My experience with the Berger hybrids mirrors yours. As they become more widely available, I intend to use them in place of VLD's. I really like the results I have gotten using Hybrids so far.
I don't think we are very far apart, if at all, regarding the effects of seating depth on pressure. You are undoubtedly correct that there are multiple variables involved. I am by no means an expert on the subject. These guys know more than I do:
Effects of Cartridge Over All Length (COAL) and Cartridge Base To Ogive (CBTO) – Part 1 | Berger Bullets
What they have to say touches on the pressure effects of both seating depth and distance to the rifling, like you mentioned. It is possible that the two variables could cancel each other out.
However, my seating depth tests cover .120 difference from one end to the other. Couple that with the fact that I often find myself working with cartridges like 6.5x55, 6.5-284, and .264 Win Mag, all of which have pretty sketchy reloading data available. I tend to push all three of them toward max loading levels. The seating depth variables may cancel one another out and they may not. My problem is that I don't know which way it's going to go and I don't want to find out the hard way that I guessed wrong. I prefer to err on the side of caution, taking into account my own loading methods and goals.
As I stated before, I don't really think there is a right or wrong answer to which order you test in. I just know which one I feel more comfortable with. I have done it both ways, but the way I am doing it now works better for me.