The effect of pressure to 100 kbar on the Mössbauer resonance has been measured for Co57 (Fe57) in Cu, V, and Ti. Using Bridgman anvils, it is possible to establish the f number as a function of pressure. For Cu the characteristic temperature θ calculated in this way compares closely with that obtained from x-ray Bragg line intensities or room-temperature specific heats. For Ti the comparison with room-temperature specific-heat data is good. For V the θ we obtain compares closely with low-temperature specific-heat values for impure samples, but is low compared with values obtained on very pure samples. The isomer-shift changes with pressure are analyzed briefly in terms of 4s-3d electron transfer.