Hey! I found an A prefix stamped above the serial # on the receiver ring and on the bolt handle. There is an X above a 95 stamped to the right side of the letter A. Directly below the serial# is a arrow, then below that is stamped EFD and below that is 10. Will try to get some pics on here. The stampings are quite small so I might not be able to photo them well enough to really see. I used a jewelers loupe to be able to see them.