Need help IDing .223/5.56 bullet

) Hi all need some help with some ID of this round. My neighbor gave me a box of .223 / 5.56 ammo that his late friend who was a Navy Seal has left at his house years ago . !

Looks like a Frangible RRLP (Reduced Ricochet – Limited Penetration) made by by Black Hills Ammunition, Rapid City, South Dakota.


From Jane’s Ammunition book:

The MK255 Mod 0 (3.24 g bullet) has a DODIC number of AA40 (it has also been designated as the MK311), but the current Mod 1 (4.0 g bullet) is referred to as the AA17.