The G23 is a mid-size service pistol, shooting the .40 S&W pistol cartridge, a standard law enforcement round with proven knock down power. The GLOCK 23 is a short-recoil operated, striker-fire semi-automatic pistol. The Safe-Action trigger system makes shooting in stressed situations infallible. The main frame of the GLOCK pistol is constructed of high-strength polymer that is resistant to shock, caustic liquids, and temperature extremes.