Neck is tight I think it's .003. At any event, once the virgin cases are fired the issue goes away. Even with virgin brass I was getting around .5-.75 MOA. This is the first cartridge I ever had where I had to neck down brass. I think I'll be staying away from these in the future. As I stated previously, I would stick with a 243 for simplicity. But I still like the 6x47 cartridge after the cases are fire formed.