The "U.S. Property" marking was placed on the receivers made at Savage as they were manufactured for Lend-Lease to Commonwealth forces. The marking ensured, legally, that what the US was providing (or lending) the British was theirs to lend. I have seen some rifles that had the marking ground out, which according to some sources, was done at the unit level by commanders who did not like to see it on rifles in British hands. Most, however, seemed to have remained intact.