Radway Green, 7.62mmx51mm Tracer round???? Dated 1960?
Mmm..... don't know much about bullets but seems standard to me, Radway Green, 1960 (an early date) NATO mark, L2A2 std ball round ? Only thing that looks different to me is that the case may have been copper coated, maybe a proof round ?
Where is Paul the Grenade when you need him?