I wish I had my 4 minutes back.
This gentleman seems good natured and pleasant with his youtube hairdo, but he is not someone I would loan a knife to.
He calls the standard Buck 110 laminated handle wood "ironwood", but seems to understand it is a laminate and not actually desert ironwood. (Dymondwood is the trade name I believe).
But the complaint about swelling is sad because he goes on to say he has been slathering the solid ebony wood knife handle with WD40. The swelling is likely from the genuine ebony wood absorbing this petroleum product. WD40 is fine for steel blades and metal on guns, but for goodness sake do not let it soak into any real wood, bone, or stag.
Wood should get real tung oil or Tried & True Danish Oil only.
This guy is creating his own problem.
And ebony is not at all absorbent of moisture- it is quite stable, so I suspect he must he soaking this knife handle in WD40......!
Not Bucks fault.