12 clicks is spec, according to bushmaster.
any more, you have a problem.
however, if it's zero'ed, you can just use it. the only trouble you would have is if your type of shooting requires windage adjustment. most shooters don't touch the windage.
if you are 1/2 way over on adjustment, give Bushmaster a PHONE CALL and they will issue a UPS call tag to pick up the upper and fix it.