Don't assume!! I've seen too many shotguns on which the sights needed to be adjusted after barrel removal even when the magazine cap and magazine tube were marked prior to removal then reassembled lining up the marks. Shooting a few patterning shots after reassembly, and making any needed adjustments will not only insure that your POI/POA are on, but will give you added confidence in your shotgun. The time, effort, and expense is well worth it.