Shoot only one shot

Loaded with more than one cartridge in the chamber.

Breech closure is in line with the bore at all times

The breech mechanism is cycled by an external lever below the receiver

A movable forearms is actuated which is parallel to the barrel

Requires a separate pull of trigger for each shot fired

Feeds cartridges, fires and ejects as long as trigger is depressed.

Used by military on combat. This is seldom encountered by firearms examiner. The largest gun ever used in combat was Gustav gun.

A light and portable machine gun

Loads, closes, fires and deloads single cartridge.

Side by side barrel or over and under

The operated by means of sliding lever under the barrel

The same as auto loading rifles, the recoil action reloads the gun from the magazine.

A muzzle-rifled at the last 2-3 inches of the barrel, used to spin the paradox bullet.

Fire tear gas and other forms of disabling gasses

Designed for wild animals. It could be with the use of bullet of poison charge.

These are known as freakish devices

Maybe used to drive stud, punch holes, and which are also capable of accudentally firing live ammunition

Homemade guns in various designs

Have 2 or more barrels in one firearms

Made by the US government capable of firing .45 cartridges, single shot and smoothbore

Used in sending signals and used in seeing enemies in the dark

Are used in hunting large fish