World War I

One of the first uses of incendiary ammunition

Ammunition

Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...

 occurred in World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. At the time, phosphorus

Phosphorus

Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...

—the primary ingredient in the incendiary charge

Incendiary device

Incendiary weapons, incendiary devices or incendiary bombs are bombs designed to start fires or destroy sensitive equipment using materials such as napalm, thermite, chlorine trifluoride, or white phosphorus....

—ignited upon firing, leaving a trail of blue smoke. They were also known as 'smoke tracer' for this reason. The effective range of this bullet was only 350 yards (320 m

Metre

The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology...

), as most of the phosphorus would burn out by then. Incendiary rounds (called 'Buckingham' ammunition) were supplied to early British night fighter

Night fighter

A night fighter is a fighter aircraft adapted for use at night or in other times of bad visibility...

s, for use against zeppelin

Zeppelin

A Zeppelin is a type of rigid airship pioneered by the German Count Ferdinand von Zeppelin in the early 20th century. It was based on designs he had outlined in 1874 and detailed in 1893. His plans were reviewed by committee in 1894 and patented in the United States on 14 March 1899...

s trying to bomb the British Isles. Filled with flammable hydrogen

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

 gas, the Zeppelins were susceptible to fire (non-incendiary rounds would pass through without igniting the gas). Similarly, incendiary ammunition was used against non-rigid observation balloons. In the British Royal Flying Corps

Royal Flying Corps

The Royal Flying Corps was the over-land air arm of the British military during most of the First World War. During the early part of the war, the RFC's responsibilities were centred on support of the British Army, via artillery co-operation and photographic reconnaissance...

 it was forbidden to use incendiary rounds for air-to-air combat with another airplane; only if balloons were being attacked was incendiary ammunition allowed, the pilot was restricted to shooting the balloon itself (rather than the crew), and the pilot was required to carry on his person written orders to carry out a balloon attack using such ammunition, as the use of such ammunition against personnel was at first considered to be a violation of the St. Petersburg Declaration.

World War II

During World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, incendiary rounds found a new use: they became one of the preferred types of ammunition for use in interceptor fighters

Interceptor aircraft

An interceptor aircraft is a type of fighter aircraft designed specifically to prevent missions of enemy aircraft, particularly bombers and reconnaissance aircraft. Interceptors generally rely on high speed and powerful armament in order to complete their mission as quickly as possible and set up...

. They were not nearly as effective at puncturing enemy bomber aircraft as armor piercing rounds, but were far more effective than standard rounds because they could also ignite fuel when they came into contact with a fuel tank or pipeline. Incendiary rounds were developed in Britain following the failure of a Swiss-developed incendiary (De Wilde ammunition) when it was tested for use in the new 8 machine gun fighters being brought into service (the Hurricane and Spitfire). A round with similar incendiary capabilities was developed by Major Dixon at the Woolwich Arsenal, and was adopted by the UK forces as the 0.303 Incendiary B Mark VI. It was initially called 'De Wilde' ammunition, even though the design was almost entirely changed. The B Mark VI incendiary bullet was packed with nitrocellulose

Nitrocellulose

Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...

 and a small steel ball was placed inside the tip of the bullet to ensure that impact would cause the nitrocellulose to explode on impact; the M Mark VI was a true incendiary round rather than a tracer round.

One fighter pilot, who was shot down by incendiary rounds while flying in the Battle of Britain

Battle of Britain

The Battle of Britain is the name given to the World War II air campaign waged by the German Air Force against the United Kingdom during the summer and autumn of 1940...

, describes his experience:

According to Joseph Folino of the 691st Tank Destroyer Battalion, he and his men were equipped with both high-velocity armor piercing and incendiary shells. When they mistakenly fired an incendiary shell at a tank, he described it as "the best thing that could have happened." The phosphorus exploded inside the tank, and raised the temperature so much that its crew surrendered immediately. He also said that their phosphorus rounds could burn through anything, even steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

. Phosphorus rounds also became a favorite of tankers, who used them both in the Normandy

Normandy

Normandy is a geographical region corresponding to the former Duchy of Normandy. It is in France.The continental territory covers 30,627 km² and forms the preponderant part of Normandy and roughly 5% of the territory of France. It is divided for administrative purposes into two régions:...

 hedgerows and to deal with larger German tanks

Panzer

A Panzer is a German language word that, when used as a noun, means "tank". When it is used as an adjective, it means either tank or "armoured" .- Etymology :...

. Phosphorus rounds could easily clear out machine gun

Machine gun

A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....

 nests, or other light emplacements. American tankers also discovered that a phosphorus round that struck near the air intake

Intake

An intake , or especially for aircraft inlet, is an air intake for an engine. Because the modern internal combustion engine is in essence a powerful air pump, like the exhaust system on an engine, the intake must be carefully engineered and tuned to provide the greatest efficiency and power...

s of a German tank engine would fill the interior with smoke, fooling the crew into believing their vehicle was aflame and abandoning it.

Modern

Incendiary projectiles, in particular those intended for armor penetration, are more effective if they explode after penetrating a surface layer, so as to explode inside the target. Additionally, targets with onboard electronics or computers can be damaged by metal fragments when they explode on the surface. Ignition is often delayed by varying means until after impact.

Some explosive projectiles, such as high-explosive incendiary rounds, contain an incendiary charge, intended to ignite explosives within the shell.