As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PREFLIGHT THE PILOT NOTICED THAT THE LMG DOWNLOCK PIN (P/N-D60-3237-11-34) HAD NO RETAINING CLIP(P/N-DIN471-08-VERZ) AND HAD SHIFTED AFT. THE FORWARD DOWNLOCK HOOK WAS COVERING ONE HALF OF THE HOLE SINCE THERE WAS NO PIN TO STOP ITS MOVEMENT. THE REMAINING CLIP BROKE IN HALF WHEN IT WAS REMOVED. IT APPEARED TO BE BRITTLE. A NEW PIN WAS INSTALLED WITH NEW CLIPS. THOSE CLIPS HAD MORE SPRING TO THEM. ALSO, THE GROOVES IN THE PIN ARE VERY SHALLOW.