I have had it happen to me 3 times throughout the years, Hornaday, Sierra and the most recent was Hammer, and it was only 1 bullet from each box of the 3. all were either smaller or larger diameters. If you don't feel it when you pick it up you will definitely know it when you go to seat it. I didn't notify any of the 3. I had other bullets of the same diameter and weight so it wasn't that big a deal to me.