I purchased a complete 16" upper from BCM just over a year ago, but due to life/scheduling, I just got the rifle out to zero the sights last week. Using Troy fixed sights, I needed 21 clicks right windage to get on target at 50m. From what I've read, this is out of spec. I can't attest to the straightness of the rail system, which is a Midwest Ind. T12G2, however, the barrel, at the end of the rail, is offset 1mm to the left inside the rail. It seems to me, that if the rail is indeed straight, the incorrect barrel indexing/alignment could be accountable for my extreme windage adjustment, at least in part. From what I can tell, the sights are level on the rail.
This is my first rifle and AR, so I'm not very knowledgeable of what steps I should take to correct this issue. Should I take the gun to a smith to verify the issue? Contact BCM? Ignore it? What other precautions do you recommend before I take any action? Please keep in mind I currently live in an apartment with few tools and no workspace. Thanks for your time.