I rented the game, I will pop the Xbox on and check. I do not remember seeing an XCR.
It does have some licensed guns in it though. What I remember seeing in the rifle section was:
HK G36,
AUG (whatever the Microtech 556 is supposed clone)
SAW
FAMA (called something else)
Big Ass Mini Gun (not really called that, just is a big ass Mini Gun)
Grenade launcher (shoots grenades)
There are more guns, but nothing to get too awful excited about.
But alas there is no XCR. The closest thing to it is a standard M4 carbine thing. It looks like a standard one, nothing like an XCR. But as far as that looking like an XCR in the picture, yeah, it does.
The game is actually pretty fun. Its somewhere between being realistic and arcade-like.
I would compare it to Gears of War. Its Gears of War with more of a present day theme with a lot more language and you are shooting people instead of bug-men.
I dunno about buying it but it is definitely worth renting.