Abstract The domain wall (DW) propagation in magnetically bistable Fe 74 Si 11 B 13 C 2 amorphous microwires with metallic nucleus diameters of 12–16 μm has been investigated in order to explain high DW velocities observed in Sixtus–Tonks like experiments. In micrometric wires, the boundary between two head-to-head domains is very elongated. The DW mobility normal to the wall surface is reduced by the domain aspect ratio and is in the range of a few m/s/Oe in the linear regime. The experimental results in the viscous regime could be quantitatively explained in terms of the domain length and normal mobility limited by the eddy currents and spin relaxation losses.