As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO DEPARTURE DUE TO AN AFT CARGO FIRE INDICATION, FIRE BOTTLE BLOWN. AN EMERGENCY WAS DECLARED. REACHING FL 300 AFT CARGO FIRE LIGHT ILLUMINATED. QRH PROCEDURES COMPLIED WITH BOTTLE USED. REPLACED CARGO FIRE BOTTLE PER AMM 26-23-01. ALL OPERATIONS CHECKS ARE GOOD. REPLACED THE COCKPIT FIRE CONTROL MODULE IAW AMM 26-00-02.