I got a call from Federal today. Some of you may have the same issue with the lot numbers not being on the back of the box, like three of the boxes I have. The nice lady that called asked me what kind of primers were on the rounds. I told her that they were small pistol primers, then she asked if they were gold or silver. I told her they were gold, she said those were fine to shoot. Also the lot numbers are very small and inside the flap (right side) of the box. I hope this helps someone. Please make an effort to call Federal to make sure though.