The game runs in even numbered resolutions so there is no center line of pixels on the X or Y axis.

The gun sights are never going to be right on a pinpoint, the center is between 2 pixels x and y.

By making a scope cross you are actually blocking more of the view than if you are using the default skin. Especially the scopes that black out the outside ring.

the best scope I made so far dithers the center pixels. The color on all 4 middle pixels is different too so you can tell exactly where dead center is. There is also a 50% transparency so you can see through the site. The semi cross i made is at 25% opacity, so there is a hint where the center pixels are.

I downloaded 2 scopes last night, and both where off center, and blocked more of the view than the default skin. the crosshair HAS to be 2 wide, or the sites are going to be really off.

makes sense but i disagree on the sniper cross part
my scope i use it perfectly centered and i never miss with it except due to the spread from the semi