One of the AR-15 rifles I resently zeroed has a problem, the windage is all the wa over to the left almost agains the stops. Is there any way to re-mount the sights to center the windage?
If using just the rear sight for elevation adjustments, check to see if your front sight is bent.
If not, then consider checking the barrel mounting. You might be able to get some more windage by loosening and retightening the barrel. Wouldn't be the first time I saw a barrel that was canted.