They were designed as cavalry pistols, during the flintlock era and being smoothbore gave you ammunition options. Close is the effective range of the pistol, unless you are shooting at a larger mass/group of soldiers/cavalrymen, probably within ten yards. Maybe help get you out of a jam, during a cavalry fight. The saber was still considered the primary arm.
I recently acquired one of these for $150....plus $40 to replace the missing top jaw and screw! Have everything that I need to fire it, just not the time, right now. Maybe in early July.