A blade outer air seal (BOAS) casting core has first and second end portions and a plurality of legs. Of these legs, first legs each have: a first end joining the first end portion; a main body portion; and a second end. Second legs each have: a second end joining the second end portion; a main body portion; and a first portion. At least one of the second legs may have its first end joining the core first end portion and a plurality of apertures in the main body portion. Alternatively, at least one of the first legs may have its second end joining the core second end portion and a plurality of apertures in its main body portion.