I've never had a problem with bullet diameter and I've shot literally thousand of NBT's in .30 caliber. Call up Nosler, tell them what you've found, you'll probably talk to a guy named Mike. I had a problem with several boxes that I had purchased being short a bullet and they promptly sent me out two new boxes for free. Try this route and see what you come up with, if they fouled bad make sure you're using Sweet's 7.62 solvent, it takes any copper out.
Selmer