A 60mm pilot hole is Ginormous ☺☺☺
What are you using, bolts from the Forth Bridge?
Those are the ones in the link. Before inserting dowel (oooh! matron) put a small amount of adhesive in the hole ensuring the interior surfaces of the hole are covered. Tap in gently until flush with the surface or as far as it will go.
Do not use too much adhesive or the hydraulic effect will make it difficult to tap down the dowel to the bottom of the hole.
lol lol, oh you've both made me giggle so much. I can't stop imagining myself drilling into ships and bridges with a 60mm drill piece now. It's only 6mm, thanks for the link chris, I wouldn't have brought the right size without it. Thanks for the tips too slack alice, you've really helped me get out of a sticky situation