If it is a Pietta contact EMF. Take a look at their Pony Express model with the Bisley hammers. I have two Pietta EMF GW II's that had the standard hammer. I contacted EMF about purchasing the Bisley hammers and did so. Dropped them in, worked the action a few times, took them out buffed down the contact areas then put them back in. Work just fine, no sear work.