A few days ago I loaded some 45-70 cartridges with 300 gr. Sierra bullets. The case is slightly bulged out for about 180 degrees around the case where the bullet is. I don't have any concentricity measuring tools, but I've got to believe these have a slight problem. I also see this crop up in 444 Marlin and 375 Winchester. Maybe the problem is case wall uniformity, or the seating stem, or something else.
What strategies to you have for keeping straight wall ammunition concentric?
