Air travel with firearms and ammunition involves a number of laws, regulations and practices that travelers with firearms or ammunition must comply with and should be familiar with before travel. The main rules are set by the International Air Transport Association (IATA), but there are a number of local variations between airlines and local laws that sometimes are conflicting.[ citation needed ]
Ammunition categories are used to define firearm ammunition types considered safe for transport. The UN Division system and UN Number system categorizes any explosive material by the speed of burning and amount of explosive. The United Nations has also instituted a categorisation system specifically for handgun ammunition. Both these systems can be used together to define safe amounts of ammunition that can be carried on various modes of transport, including civilian scheduled flights.
The phrase Div. 1.4S, UN 0012 or UN 0014 denotes the categories of ammunition that the IATA permits to be carried on passenger flights. In simple terms, each passenger may carry up to 5 kg of weapons cartridges of less than 19.1 mm caliber being either blanks or with solid projectiles, in their checked baggage. The IATA published the minimum requirement for an airline for the carriage of dangerous goods in a table, where ammunition of the following nature can only be carried subject to the following permissions and approvals:
Ammunition (cartridges for weapons), securely packaged (in Div. 1.4S, UN 0012 or UN 0014 only), in quantities not exceeding 5 kg (11 lb) gross weight per person for that person's own use, excluding ammunition with explosive or incendiary projectiles. Allowances for more than one passenger must not be combined into one or more packages.
- Permitted in carry on baggage: NO
- Permitted in or as checked baggage: YES
- Permitted on one's person: NO
- The approval of the operator(s) is required: YES
- The pilot in command must be informed of the location: NO
Local gun laws may deviate from IATA rules by prohibiting it with some types of weapons or having special rules for transport that sometimes conflict with IATA regulations.[ citation needed ] Airlines may also have their own rules and procedures that sometimes conflict with each other, with IATA rules or even local laws and regulations. For example, some jurisdictions require the firearm and ammunition to be transported in separate cases, while other jurisdictions require them to be transported in the same case.[ citation needed ] This may, depending on jurisdiction, be solved by using two or more separate cases fitted inside a common larger case.[ citation needed ] Some jurisdictions even require integral parts of the firearm to be disassembled and put into two separate cases, while others require the firearm to be complete.[ citation needed ] Travelers are therefore encouraged to check all relevant regulations depending on where they travel, both in regards to the departure, destination and any stopovers.  Permits or licenses may be required.
Firearm cartridges in general are regarded as being constructed such that they pose little danger during fires. If ignited by intense heat the cartridge will burst, but the particles will typically not travel very far, and protective firefighter clothing is generally considered sufficient to stop the fragments. 
However, if cartridges are stored in an airtight metal chamber, dangerous pressures may occur during a fire.  For this reason, it is generally recommended to transport ammunition in original boxes sold by the manufacturer or plastic boxes intended for safe transport.
Most types of civilian firearms ammunition is classified as division 1.4S. The division 1.4 in the UN explosives shipping classification system covers cargo with minor explosion hazard, while the suffix "S" refers to the packaging being made so as to not hinder nearby firefighters. Division 1.4S is referred to by IATA as follows: 
Articles and substances that present no significant hazard. This division comprises articles and substances, which present only a small hazard in the event of ignition or initiation during transport. The effects are largely confined to the package and no projection of fragments of appreciable size or range is to be expected. An external fire must not cause virtually instantaneous explosion of almost the entire contents of the package.
Note: Articles and substances in this division are placed in Compatibility Group S when they are so packed or designed that any hazardous effects arising from accidental functioning are confined within the package unless the package has been degraded by fire, in which case all blast or projection effects are limited to the extent that they do not significantly hinder fire-fighting or other emergency response efforts in the immediate vicinity of the package.
The United Nations has categorised all forms of dangerous goods, and the categories regarding explosive materials are listed at List of UN numbers#UN 0001 to 1000. The most relevant UN numbers for civilian ammunition transport is UN 0012 and UN 0014.
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries.
Gun laws and policies, collectively referred to as firearms regulation or gun control, regulate the manufacture, sale, transfer, possession, modification, and use of small arms by civilians. Laws of some countries may afford civilians a right to keep and bear arms, and have more liberal gun laws than neighboring jurisdictions. Countries that regulate access to firearms will typically restrict access to certain categories of firearms and then restrict the categories of persons who may be granted a license for access to such firearms. There may be separate licenses for hunting, sport shooting, self-defense, collecting, and concealed carry, with different sets of requirements, permissions, and responsibilities.
A cartridge or a round is a type of pre-assembled firearm ammunition packaging a projectile, a propellant substance and an ignition device (primer) within a metallic, paper, or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for the practical purpose of convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often informally used to refer to a complete cartridge, it is correctly used only to refer to the projectile.
Checked baggage is luggage delivered to an airline or train for transportation in the hold of an aircraft or baggage car of a passenger train. Checked baggage is inaccessible to the passenger during the flight or ride, as opposed to carry-on baggage.
Firearms in Canada are federally regulated through the Firearms Act and related provisions of the Criminal Code. Regulation is largely about licensing and registration of firearms, including air guns with a muzzle velocity of more than 500 ft/s or 150 m/s and muzzle energy greater than 4.2 ft⋅lb or 5.7 J.
In the United Kingdom, access by the general public to firearms is subject to some of the strictest control measures in the world. However, fulfilment of the criteria and requirements as laid out by the laws results in the vast majority of firearm licence applications being approved. Laws differ slightly in Northern Ireland due to Northern Ireland having its own firearms legislation. Concerns have been raised over the availability of illegal firearms.
Caseless ammunition (CL), or rather caseless cartridge, is a configuration of weapon-cartridge that eliminates the cartridge case that typically holds the primer, propellant and projectile together as a unit. Instead, the propellant and primer are fitted to the projectile in another way so that a cartridge case is not needed, for example inside or outside the projectile depending on configuration.
Firearms regulation in Finland incorporates the political and regulatory aspects of firearms usage in the country. Both hunting and shooting sports are common hobbies. There are approximately 300,000 people with hunting permits, and 34,000 people belong to sport shooting clubs. Over 1,500 people are licensed weapons collectors. Additionally, many reservists practice their skills using their own semi-automatic rifles and pistols after the military service.
An automatic firearm is an auto-loading firearm that continuously chambers and fires rounds when the trigger mechanism is actuated. The action of an automatic firearm is capable of harvesting the excess energy released from a previous discharge to feed a new ammunition round into the chamber, and then ignite the propellant and discharge the projectile by delivering a hammer or striker impact on the primer.
A blank is a firearm cartridge that, when fired, does not shoot a projectile like a bullet or pellet, but generates a muzzle flash and an explosive sound like a normal gunshot would. Firearms may need to be modified to allow a blank to cycle the action, and the shooter experiences less recoil with a blank than with a live round. Blanks are often used in prop guns for shooting simulations that have no need for ballistic results, but still demand light and sound effects, such as in historical reenactments, special effects for theatre, movie and television productions, combat training, for signaling, and cowboy mounted shooting. Specialised blank cartridges are also used for their propellant force in fields as varied as construction, shooting sports, and fishing and general recreation.
Dangerous goods, abbreviated DG, are substances that when transported are a risk to health, safety, property or the environment. Certain dangerous goods that pose risks even when not being transported are known as hazardous materials. An example for dangerous goods is hazardous waste which is waste that has substantial or potential threats to public health or the environment.
20 mm caliber is a specific size of popular autocannon ammunition. It is typically used to distinguish smaller-caliber weapons, commonly called "guns", from larger-caliber "cannons". All 20 mm cartridges have an outside projectile (bullet) diameter and barrel bore diameter of 0.787 inches (20.0 mm). These projectiles are typically 75 to 127 mm (3–5 in) long, cartridge cases are typically 75 to 152 mm (3–6 in) long, and most are shells, with an explosive payload and detonating fuze.
On the commercial transportation, mostly with airlines, the baggage allowance is the amount of checked baggage or hand/carry-on luggage the company will allow per passenger. There may be limits on the amount that is allowed free of charge, and hard limits on the amount that is allowed.
The following are terms related to firearms and ammunition topics.
Ammunition is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons and the component parts of other weapons that create the effect on a target.
This is a list of laws concerning air guns by country.
The UN Recommendations on the Transport of Dangerous Goods are contained in the UN Model Regulations prepared by the Subcommittee of Experts on the Transport of Dangerous Goods of the United Nations Economic and Social Council (ECOSOC). They cover the transport of dangerous goods by all modes of transport except by bulk tanker. They are not obligatory or legally binding on individual countries, but have gained a wide degree of international acceptance: they form the basis of several international agreements and many national laws.
The Firearms (Amendment) Act 1988 is an Act of the Parliament of the United Kingdom, which is still in force. The Act, as amended, tightens controls on the possession of firearms, and applies throughout the whole of the United Kingdom except for Northern Ireland. On 15 November 1988, the Act gained Royal Assent. The Act was partly in force at Royal Assent. On 1 February 1989, fourteen sections of the first 25 sections of the Act came into force. On 2 April 1991, the Act came wholly into force.
The Afanasev Makarov AM-23 is a Soviet designed aircraft autocannon that has been used in a number of aircraft in the Soviet Air Force. Its GRAU index was 9-A-036. It was often used in place of the earlier and slower-firing Nudelman-Rikhter NR-23.
In firearms and artillery, the primer is the chemical and/or device responsible for initiating the propellant combustion that will push the projectiles out of the gun barrel.