Single crystals of NiBr and FeI boracites have been grown using a sealed-ampoule, vapour phase transport technique. Small polished plates cut from FeI boracite crystals have been poled using the Camlibel high voltage pulse technique. Measurements of the pyroelectric and dielectric properties of these crystals are presented as functions of temperature, together with measurements of the dielectric properties of NiBr boracite. It is concluded that FeI boracite shows a pyroelectric figure-of-merit which increases rapidly with temperature, becoming comparable with that of TGS at temperatures above 60°C.