  We have used effective reaction rates (ERR) for the helium burning reactions
to predict the yield of the gamma-emitting nuclei 26Al, 44Ti, and 60Fe in core
col- lapse supernovae. The variations in the predicted yields for values of the
reaction rates allowed by the ERR are much smaller than obtained previously,
and smaller than other uncertainties. A "filter" for supernova nucleosynthesis
yields based on pre-supernova structure was used to estimate the effect of
failed supernovae on the initial mass function-averaged yields; this
substantially reduced the yields of all these isotopes, but the predicted yield
ratio 60Fe/26Al was little affected. The robustness of this ratio is promising
for comparison with data, but it is larger than observed in nature; possible
causes for this discrepancy are discussed.
