1896 ca, ZURICH, SWITZERLAND: The swiss engineer and inventor Professor FRIEDRICH WILHELM (F.W.) HEBLER (1844-1932). Inventor of Hebler Cartridges. was a mechanical engineer from Bern but spent most of his time in Austria. In collaboration with Karel Krnka, he developed the copper jacketed bullet along with advancements in bullet aero-dynamics. From 1874-1891, Hebler carried out countless experiments conceming cartridge design. He was particularly interested in what he called the smallest caliber and published a series of books on this subject from at least 1886 to at least 1894.