Reply by PurpLev

what you might want to try is this:

1. on the top part, enlarge the inside of the hole so that you’ll have a groove in the deeper end
2. drill a small hole on the top of the dowel
3. put a short rod type wedge in the top of the dowel that if pushed into the hole will enlarge the top of the dowel
4. put the top on top of the not-yet-wedged dowel
5. strike it all down

the top will press the pin into the dowel as it sets in which should expand the dowels top into the groove you made in the top’s hole and will lock it in

-- ㊍ When in doubt - There is no doubt - Go the safer route.