I have some experience in hatchet handles,although it`s whole different method of fitting.Unlike for example walnut ,which once dried is very stable,hornbeam "works", it seems to me, forever.Just when think it`s,at last, dried and settled five hot dry days and axe head is loosen.We fix it submerging axe head in water for a few hours.But I don't think it would work on hawk.For hawk˙s handle is more lighter,longer,delicate,then hatchet`s,and under more stress,and repeatedly submerged and dried areas eventually rot.And axe haft is not much expensive or hard to tiller every few years .So I plan to dry wood ,rough shape haft,dry it slow again in dry and airy place,then shape it to fit firmly an then submerge in linseed oil for week.Linseed oil swells the wood and does not evaporate.And it protect it.Or to buy some hoe haft and skip drying,just tiller and some final drying.That is my plan if thing breaks-and I think it will,for Rifleman`s is very heavy and I˙m not very good thrower.With hawk.Hatchet throwing works better for me.But have to learn both.