It's the Colt model stamped 5.56.
Before adding the scope:
With the NcSTAR 3x - 9x scope:
I'm just waiting for the "new" range to open up in North Las Vegas in June. I would "like" to battlesight zero the iron sights (at 25 meters) as well as the scope. I can use both because the scope sits above the iron ones. Although I'll be more inclined to use the scope because I can't pop the 300 meter target with the iron sights like I was able to do while in the Army over 30 years ago.
Eyesight is definitely not
the same now.....