Usual (transverse) Ampere force appears due to the charges pressure on the side wall of a conductor. Their transverse deflection is caused by the Lorentz forces. Electric field In longitudinal direction of a conductor pushes free electrons forward. This electric field is caused by electrons shifting and should push atoms of the conducting medium also in the current direction.

The experiments on longitidinal Ampere force show conductor breaking caused by longitudinal stretching, repulsions, reactive jets in conductive liquids or plasma. All these effects may be explained by coulomb pressure of the moving charges on the medium: independently on the current direction because of third Newton law acting in nearby conductor segments of the same or different structure (solid/liquid).