I just picked up the newest issue of Handloader Magazine. Took a look and the author of one of the articles was saying that about 20% of all of winchester and remington case necks are not concentric which makes the bullet sit slightly crooked in the case mouth when seated. He stated that this will make the bullet "wobble" into the rifling which in turn makes shots less accurate. He said that Lapua and Norma brass are the most concentric and tends to eliminate that problem. He said also that if you want to seat the bullet properly and ensure a nice straight fit into the case that one should use the competition seating dies because of the tight tolerances of these dies. There were some other options that he threw in there but these are the ones that stuck out to me. Anyone buy this? Im not saying that it isnt true but does it really make a big difference or is it just a few things that add up to make better accuracy? Thoughts?