No it may not stay the same. Reloading is always a giant experiment with more variables than can be controlled. Any change in any one of those variables can produce changes in results. Or it may not.Thanks for the replies!
One more question: Let's say I finally find the magic bullet depth. I'm not shooting bench rest, so I'm not looking for that accuracy. However, once I find the depth, will that stay the same, while going from one powder to the next? From one bullet weight to the next (55gr to 62gr.)? Shell to shell?