Well yeah, if the powder doesn't change position due to density or filler, then the position is consistent and the burning characteristics won't change.
I've seen a lot of variations using 2400 and Unique in both '06 and .30-30, enough so that for my .30-30 "turtle loads" that mostly will be fired at a declination but have to sustain being shuffled-'n'shucked from the magazine justify using a "powder locator" such as a 3/4 grain tuft of Dacron fluffed and lofted to fill the airspace between powder and bullet and put a slight spring tension on the powder charge to hold it in place.
Gear