Don't worry about it. The only thing that counts is tightness of the group on target and I have found that things one does with reloading makes little difference on target. I have tested clean brass vs dirty brass, trickled powder vs dropped powder, various seating depths etc. These factors are dwarfed by other factors such as trigger control, correct wind reading, correct DOPE, quality of bullets, quality of barrel on your rifle etc. I have lots of seater dies, including Forster bench rest, RCBS and Lee because I set up a seater die for a bullet type and then keep it for that bullet type. All of them show some variation in seating depth results and it has no detrimental effect on group size on target. I even use a spare .308 RCBS seater die to seat one of the bullet types in my .243 as it was going spare and again it has no detrimental effect even though the channel inside the .308 die is much wider than it should be for a .243.