The pressure dependence of antiferromagnetic ordering in Cr&sngbnd;Ru, Cr&sngbnd;Mn, and Cr&sngbnd;Re alloys has been investigated. At low concentrations,TNdrops very rapidly and nonlinearly with pressure up to some point and then exhibits a much slower variation with a distinct break in slope. We attribute this break in slope to a transition from communsurate phase (C) at lower pressures to an incommensurate phase (I) at higher pressures. If we extrapolate the paramagnetic (P) to incommensurate boundary back to 1 atm we obtain values for the Ne´el temperature (TNI) forP‐Itransition, if theP‐Ctransition had not occurred first.TNIwhen plotted againste/ashows a sharp break at pure Cr, in accord with theoretical predictions based on the ``depairing'' effects of impurity scattering.