yes, very common, and we've talked about this off and on for many years, the stamping "jig" fixture left a lot to be desired and had to be "manually" adjusted (rotated) after each gun stamping, so newer stamps in with older ,worn ones and the changes if any broke at any time, , and who may have supplied them and on and on, and with the errors that occurred, we then got the "D" guns, when numbers got 'duplicated' OR skipped over, or ?????????? Ah, the joys of manufacturing and having to number each and EVERY gun, keep things in order and running smoothly as well as FAST !!!!!!talk about a stress filled job, hope he did not drink......... :roll: