What was found
RT MAIN GEAR DIDN'T INITIALLY COME DOWN WHEN SELECTED. GO AROUND INTIATED MAINTAINING APPROX 170 KNOTS. QRH REFERENCED, GEAR CAME DOWN AFTER APPROX 2 MINUTES. LANDING UNEVENTFUL. GEAR ACTUATION HAS SEEMED TO BE SLOWER THAN NORMAL ON PREVIOUS FLIGHTS WITH AUX HYD ANNUNCIATION STAYING ON LONGER THAN NORMAL. R & R RT MLG ACTUATOR. FOUND CHIPS IN RT HYD SYS RETURN FILTER TWISTED SYS. BLED HYD SYS SEVERAL TIMES AS WELL. OPS TESTED GOOD. ALL WORK IAW MM 32-20-31 & 32-10-20.