My m&p sights were off from the factory. It took one bump from the smith to fix. If your sights are off from the factory I recommend just going ahead and replacing them unless they are already night sights or fiber optic.
check the grouping first. Make sure you can get consistent group. Then focus on sight adjustment.
It was my front sight. They told me it was off and they replaced and test fired. I still haven't had a chance to chk for my simelf yet.