I Found a supply of 5.56mm?
It comes in a Brown Box wich is marked 20 CARTRIDGES 5.56mm  BALL M193
It comes with 2 stripper Clips Loaded.
HEAD STAMP is 5.56 80.07 PS

It has red primer sealant on the primer
it is brass cased 55gr. Ball

The brown box is the same type that fits in the 7 pocket bandoliers?

If I rember right I think it could be the Old PMC ammo I use to shoot in the early 80'S??
BUT I dont remember that it came with strippers???

Thanks Troy! Can you tell the year by the head stamp? 80 or 87