In the process of powder coating lee 150 grain gas check bullets, I discovered some of the bullets wobbled when balanced on their bases on the tray for the toaster oven. To reduce the number of bullets falling over when moving the tray into the toaster oven I decided to make sure the base of each bullet was flat with no part of the sprue cut standing proud of the bullet base. This takes a couple of seconds of scraping the base with a sharp knife.
After over 500 bullets with scrapped bases power coated, and the gas check installed later through a lee 0.311 size die I discovered that my groups tightened up and I only recall one flyer that was not shooter error in the past month of shooting.
I will have to sort out some bullets with the sprue cut standing proud and see what happens with group size and flyers.