Firearms in Checked Baggage
I used 5 minute epoxy on mine about 5 years ago and it work just fine for singles and multi-feeds. Clean that groove with alcohol real well. Apply epoxy and insert feed latch. Use clamps to hold in place until glue sets.
After that, WHEN REMOVING/INSERTING TRIGGER PINS, PUSH THEM TOWARDS THE EJECTION WINDOW. Do that and the epoxy should last a good long while. Pushing the pins away from the window is the cause of the feed latch being knocked loose.