Ray-I have never seen any single digit headstamps like 4, 5 & 6 for 7, 8 or 9. Actually I doubt they exist, at least on U.S. made ammo. The closing of F.A. is probably one reason, but I think perhaps the main reason is the emergence of EDM for making bunters. Using EDM a bunter can be made for a small fraction of the cost of the older engraving method. In fact, I would guess a EDM bunter can be made for about, or less, than the cost of grinding off the extra digit from older bunters. All of this is just speculation, but this is my 2-cents worth on the subject.