Canted FSB or out of spec upper ?
So I took my BCM upper out today for the first time and I had to adjust the BUIS 33 clicks to center my shots at 25 yards. The rifle was shooting 3" to the right with the BUIS aperture centered. This BUIS was used on two different rifles and always centered my shots within a few clicks left or right so I know the BUIS is not the issue.
I took some measurements of the rail because I suspected that there might be an issue when my Larue mount from another rifle was loose when mounted to this upper.
Now I'm not sure if this needs to go back or not, that's what I'm here to ask. If it does I hope that BCM doesn't give me any issues because I had to cut off the bayonet lug for AWB compliance. I was able to take the lug off without the need to remove the FSB so I know that this in no way would mess up the alignment.
History: The upper was previously returned to BCM and replaced do to the upper being out of spec.
Images are attached and your opinions are really appreciated.
Attachment 12101
Attachment 12102
Attachment 12103