Stress-strain curves of (1-x)BiFeO3-xPbTiO(3) compositions with x=0.2, 0.3, and 0.35 were determined under uniaxial loading to assess the material's potential for domain switching. The composition with x=0.35 provides the highest remanent strain, with more than 0.2% coupled with a strong tendency to relaxation. This ferroelastic behavior is in accordance with results from R-curve measurements on the same compositions, where the material with the most remanent strain yields the highest toughening effect.