I liked (past tense) the GR sights on mine but the actual rear ring has broken off the base just above the adjustment dial. The steel is not a very thick ring and now replacing just the ring has been a hassle. No reply from mossberg after many attempts to contact them by email.
Previous inquiries to dealers etc suggest buying the entire rear mount as a replacement part rather than just the ring but that will be over $100+. No thanks.
Any suggestions on fixes, part sources, or a replacement rear sight compatible with the brazed-on front ramp are most welcome.