Originally Posted by
Ned Christiansen
I don't see a rear sight off center to be an issue..... maybe, if it's bottomed out all the way to one side.
That's why we have adjustable sights on these things. If every AR had the adjustable rear sight perfectly centered, we could do away with the adjustability. But there are just too many connections and tolerances between the muzzle and the rear sight-- it would be impossible to get every sight perfectly centered:
Front sight to barrel mounting (or):
Front sight to rail mounting
Rail to receiver
Barrel to receiver
Receiver threads
Receiver face
Barrel extension
Barrel extension locating pin to slot in receiver face
Barrel nut
Rear sight to receiver mounting
..... not to mention, tolerances in the barrel itself with regards to concentricity and straightness.
Even with the very highest quality parts, and let's say, held to 75% of the tolerances, there are still just too many joints to hope for perfection every time. The one pictured is not what I'd call a problem but I think it's very kind of BCM to take a look at it.