In late 2015, Federal Premium introduced the Syntech ("synthetic technology") line of handgun bullets for the 9mm Luger, .40 S&W and .45 ACP calibers, under Federal's American Eagle brand. The "Syntech" trademark derives from the Total Polymer Jacket (TPJ), a synthetic low-friction polymer jacketing that replaces the traditional bare lead or copper jacketing. With no metal-on-metal contact with the bore and rifling, the polymer-jacketed bullets theoretically will impose much less wear on the rifling and generate less heat, which helps to extend barrel life as well as eliminate lead and copper fouling in the bore. Cartridges using Syntech bullets also use special primers and clean-burning propellants to further minimize carbon fouling.