Glock is a series of semi automatic pistols designed and produced by Glock GmbH of Deutsh-Wagram, Austria. It has been in service since 1982. It has an extensive plastic structural content. It has a short recoil locked breech; tiliting barrel action fires amongst others a 9x 19mm Parabellum cartridge is used by the Austrian military and US Law Enforcement agencies. Glock pistols have become the most profitable line of products, taking up 65% of the market share of handguns in the United States, in spite of preliminary opposition from the market due to strength and reliability concerns.