I have found that every component of a worked up load, will change a little, if any component of that load is changed. Whether it be powder, bullet, primer, cartridge over-all-length, case, or anything else. It may be just a subtle change, but will almost always make a change.
When I start out to work up a load, I always start with the lowest charge listed, with the bullet weight I want to shoot, and load 5 rounds, with every round being loaded the same, with 4 or 5 different primers, then I try different powders, different cases, at different over all lengths, until I find the best grouping rounds. At that point I start working with charge weights until I get the groups to touch, and that is where I call it quits. I'm not a bench rest shooter, but I want to get all the accuracy out of my loads that I can, and sometimes it will take a hundred rounds or so to get just the right formula for each weapon, but once I get it figured out, I NEVER change it.