Most likely BS. True 5.56mm NATO AP ammo are black-tipped M955 rounds. Even green-tipped M855 isn't true AP ammo, it has a "steel penetrator core" that was designed to improve the round's ability to penetrate a steel helmet at 600 meters better than the original 5.56mm (M193) and 7.62 NATO ball.

if the magazine was Delta Force, they were M855 selling for about 10x the price you can get them anywhere else. What a joke.