V-I characteristics have been measured, in several monofilamenry Chevrel phase superconductors (CPS) wires made using prereacted powders of both pure SnMo6S8 (SMS) and Pb0.6Sn0.4Mo6S8 (PSMS) compounds, in applied magnetic fields up to 25T. The values of Jc in different wires lie in the range ∼ 5 × 107 −109 A/m2 at 4.2 K and 9T. In the SMS wires the critical current density Jc(B) tends to vanish at the expected ideal Bc2. In contrast, for PSMS wires the Jc(B) tends to vanish at fields much smaller than the expected Bc2 for pure PbMo6S8 (PMS) and nearer to that of SMS. The V-I characteristics at the dissipative onset are highly non-linear and show a power law behaviour V = kIn with a typical n-value (1.8K, 26T) > 17.