Due to loose tolerances in some manufacturers’ upper receivers, some hand fitment may be required.
Be sure to remove 100% of any support material from the feed ramp pocket before installing
Open feed ramp pin hole in frame 0.124″
Drill bit: https://riptiderails.com/sd9-sr9-mac-daddy-drill-bit/
(1) DB9 / Mac Daddy Feed Ramp – Aluminum
(1) 1/8″ Solid Pin