Impossible to answer without knowing the type of gun.
a shotgun
A Lewis gun was an early type of machine gun used in WW1.
If it's legal, a spear gun can be used.
matchlock
Any type a criminal can get his or her hands on.
They used rapiers which are a type of sword and a pistol which is a type of gun.
22 LR
.380 refers to the diameter of the bullet fired- and to the type of cartridge used by the gun.
Flintlock musket
the Japanese did in WWII.
a scanner, or gun.