Originally Posted by 300WinMagShooter
I am new to the Edge caliber and am having some difficulties getting the virgin brass prepped well. I am using the .300 UM brass and Redding .338 UM dies to neck up. I frequently get very poor runout on the necks (sometimes up to 8 thousanths) when I check after using the FL die, so I have been resizing again with the neck die a time or two in order to get down to 2 thousanths or so. Using the same dies on fired brass does not give me any issues. Everything is well lubed and champfered with a VLD tool. Sometimes the neck runout is more than the bullet runout. My best accuracy is when the case neck has no more than .002" and the bullet has .002" or less.
My question is this: How much does neck runout affect accuracy if the bullet runout is acceptable? How is it that the bullet runout can be significantly less than the neck runout?
Thanks in advance for any help!
I have seen this before on other cases.....
I think the source of the runout of your virgin brass is the expander ball in the 338 UM die. I only use the Sinclair expander mandrels to neck up and that makes the case forming operation very easy. Try it, you'll like it.