Wish I could help but I've never seen that "X" on an upper. Looks like Microsoft XBox or something!
The square mark on the receiver is a fairly common one that indicates where it was forged. Like car batteries, there are apparently a few places that have made tons of AR receivers over the years regardless of who sold them. Some manufacturers make their own.
The square mark on the receiver is a fairly common one that indicates where it was forged. Like car batteries, there are apparently a few places that have made tons of AR receivers over the years regardless of who sold them. Some manufacturers make their own.
