Measurements of the reactivity contributions of a number of materials have been made in the 1.5-in.-diam glory hole of the Sandia Pulsed Reactor II (SPR II). In similar measurements at Los Alamos Scientific Laboratory in Godiva, materials with very low absorption cross sections had a positive reactivity effect at the core center, but at the center of the SPR II glory hole, the same materials produced negative reactivity effects. The differences are probably due to changes in the neutron energy spectrum and scattering contributions. Results of prompt burst operations with samples in the glory hole show that changes of several cents can readily occur in the reactivity worth of the burst rod.