These Antler Half Blanks are around 2.5" long and are not drilled so you can drill them to the size required.
Gorilla or epoxy glues are recommended. The ends will need to be sanded/milled for length and squareness.
Some blanks have some pith or marrow present. Thin and medium CA can be used to fill it if needed. Please be sure that the glue is FULLY cured before you resume turning.
As a safety reminder, a dust mask should be worn when turning the Antler Half Blanks. Using sharp tools will help you turn the blanks faster and lessen the dust produced.