Neither does it have an arrow.
:P
[Edit]
Recolored the XCR, cleaned up the model a small bit, added the new reticle, a muzzle brake and a new suppressor.
Fixed the drop-weapon-while-scoping bug and added grenade trails. Lowered the P90 damage from 18/16 to 16/14.
Well if you want to be
that realistic about, the Acog on the XCR is incorrectly modeled completely. The crosshair isn't only incorrect but so is the actual model of it. The 2x20 has a reticule like this, meeting in the middle.

It's also modeled like this, yours is modeled off the more traditional/well known 4x32.

I guess I'm just nitpicking but IMO, the triangle sight (actually on the 2x20) looks better.

I was under the impression that the XCR's Acog was 4x32 because that's what it
actually is.
Real XCR with 4x32 acog.

Gravy's XCR

Same sight aside from the QD mount in the real picture. -1 realism points