This is related to the recent Forum thread " Polish 5.56 M855 for SDI 2016?": Polish 5.56 M855 for SDI 2016?
From DS Arms here is the 7.62x51mm M80 from Poland-
Note this also has a “21” at the end of “LOT 001-16-21” same as the lot designation for the 5.56x45mm M855 in the earlier thread i.e. MESKO.
Non-magnetic GM bullet