A lot of so called experts say that the powder charge is one of the least critical aspects for accuracy. Personally, I do not believe that. With over 40 yrs of reloading experience and also from results by other reloaders have shown that consistant charges results in better accuracy. Changing a charge by even one grain has also shown to increase or decrease accuracy (group size) as does changing primers. I believe case trimming aids a good deal in accuracy too. Squaring up the case mouths, having the cases all the same length for consistant pressure on the bullet. I also have found that a factory crimp die like the one Lee makes shows increase in accuracy in some cartridges. I've never turned a case neck since I've been reloading.