HighCom Security and US Cavalry respectively.
The NM carriers I've seen are heavier than normal tho the Young one does have small flutes at the front.
waste of money,...
Usually, that is caused by too great a radius on the lip of the chamber.
the barrel on an AR is not screwed into the receiver.
Never seen that, the FCG pins are held in place by the related springs, not the friction of the lower. Enlarged holes lead to improper geometry...
IIRC, the one lacking the M4 cut is an HBAR.
may wanna check
have you verfied the serial number with OAI?
Seen it before
Remove the gas tube and barrel nut, use a 1/16" roll pin through the gas tube "cloverleaf" to manipulate the head of the cam pin.
Any of the ones available for download here.
The REP is the factory proof mark.
M24s will be marked with the number of the shooter (normally two digits) that test fired the rifle...
Army Infantry, 86-92
Ft Lewis, WA A/104th and Ft Polk, La 4/6th.
Separate names with a comma.