The term handgun usually means a gun meant to be operated by one hand and having a chamber which is integral to the barrel as opposed to the other type of handgun, the revolver, which has a revolving cylinder.
Herstal FN 57
The Fn 57 is a Belgian made semi automatic pistol manufactured by FN Herstal. The FN 57 is a delayed blowback single action pistol firing a 5.7×2.8mm cartridge. It comes supplied with a 20 round magazine and has an effective range of 50m. It is currently supplied with fully adjustable sights or fixed sights.