How or what to do to test for accuracy when changing powder lots. I'm loading for a 270 win with H4350 powder and don't have a lot of data on velocities with different powder charges. I'm done some searches and cant' find the answer to this question. Do I start over and test from min to max powder charge in .5 grain increments? Or do I find the powder charge just starting to show pressure signs and then back off 2 grains? Or do I vary powder to get the same velocity of the most accurate load in the previous lot? Thanks.