Recoilless gamma-ray emission has been observed in Fe57 following Coulomb excitation by 3.0-MeV α-particle bombardment of iron nuclei in α-iron and Fe2O3 lattices. Within experimental error, the Mössbauer fraction following Coulomb excitation in α-iron is not reduced as compared with that observed in Co57 source data, whereas in the case of the oxide a reduction in the recoilless fraction by a factor of 2 is observed. In both the metallic and oxide data, the respective hyperfine splittings do not deviate by more than a few percent from the values obtained from Co57 source data for α-iron and Fe2O3, respectively. There is no indication in any of the Coulomb excitation data of isomer shifts differing from the shifts observed in Co57 source data. These results are interpreted in terms of extensive replacement collisions.