The way I understand it, consistant MV, ES are more of an indicator. If you load 20 rounds by just feeding the press cases and bullets, you might get decent consistancy, but probably not good consistancy. However, if you prep the primer pockets, de-burr the flash holes, turn the necks of the same brand of cases from the same mfg lot, your consistancy will improve. This will not (more than likely) turn a 1.5moa load into a tac driver load but will (almost always) make a pretty accurate load even better. One thing I just did for my rifle(fat barrel) is picked a clean burning powder, chose a target velocity that I wanted to shoot at, and started loading 5 rounds each at a specific bullet steating depth, and seating .005" deeper with each group of five (I started at .010" shorter than what the bullet would touch the lands at). After loading 8 groups of 5, I went to the range. My groups were: 1 1/4", 1 1/4", 1 1/16", 7/8", 1", 3/8", 1/4", 5/8", all at 100 yards, no wind. I've done this with 2 different powders at 2 different velocities, one hot, one mild. The first load of 40, I had a 5 shot group that measured 1/10" and I'm fairly sure I can get that out of the 2nd load with a bit more tinkering. Up to now I have done no case prep work other than trimming to length. This, to me, proves Ranger61's bit about harmonics... every rifle (from what I hear) has a sweet spot FOR THAT PARTICULAR LOAD, you just have to find it. After having done this I'm now trying the case prep thing to see if the groups improve more... I'm getting almost 40 fps ES hand weighing every powder charge exactly. Bottom line: I think seating depth changes can give you more bang for the buck loading for accuracy... but all the other stuff can never hurt, and velocity fluctuations will tell you that an accurate load can still be a little better. If you want to go that far...