Engraved Serial number? I don't recall that, but the I don't recalll how the serial numbers were to start with on the Americans.

One of KDF's tag lines was 3 shots under 1/2 inch, 5 shots inder 1 inch. I have a group from that .308 Norma, of 5 shots under 1/2 inch. Only ever did it once, but did do it. Never any problem with the 1 inch part with factory Ammo.