A print hammer mechanism for use in an impact printer such as a band printer or other printer which has printing elements which are impacted to make impressions on paper or other record medium. The hammer of the mechanism is impacted by dual armatures in forward motion toward the paper and return motion away from the paper so that the hammer is positively driven and does not depend upon the bounce back of the hammer from the paper or need a return spring on the hammer. This reduces the time for each hammer stroke and increases printing speed (characters per second). The armatures are normally decoupled from the hammmer and strike the hammer only after accelerating sufficiently to transfer sufficient speed to the hammer upon impact therewith. Springs are used to bias the hammer to a home position in the return direction and to maintain the armatures against a stop spaced from the hammer so that the armatures are normally decoupled from the hammer. The spring forces are light; forward and return hammer drive being provided by the armatures. A magnetic field structure for independently actuating each armature can be used for actuating the hammer in timed relationship with printing operations.