So I've heard about the different seating depth "sweet spot" for these bullets, but my question is how does powder selection play into this? I have some powder (IMR4320) that I won't use for much of anything, but is suitable for my .243. If I take my best group with a given seating depth, will it hold true with different powders at different burn rates? I figure this is the best way to go about this, since components are kind of hard to find right now. I don't want to work up a good load then have to wait months to find the powder if I run out. I plan on using either H4350 1 full LB on hand, IMR 4064 (about 1 1/4 LB on hand) or win 760, 4 LBS in stock at my local store as of last week.