I bought this one from a friend.
The specs from him were as follows:
M4A3 Custom upper built by Carolina tactical supply. Sabre defense fluted 1:7 barrel .223 match chamber with A2 FS. Daniel Defense 12.0 rail with PRI low profile gas block and 3 covers. Lower is a Rock River Arms National Match with national match trigger. Scope is a SWFA Super sniper rear focus 10X mildot reticle that is mounted in an Armalite 1 piece 30mm mount. Lower also has a hogue pistol grip. YHM Bipod mount and Harris bipod.
It had less the 500 rounds thru it when I bought it from him.
Great shooter too , best group so far is a 4shot group at .364 @ 100 yards with a 5th shot I pulled opening it up to .508
I been reading here for awhile , had a bit of trouble getting my account to work but expect to see me reading and posting more.