The explosive charge within a shell is known as the "Bursting Charge" or, more simply, as the "Burster." Some of the more well-known:

Black Powder or Gunpowder - Used as the burster in most shells prior to the early years of the twentieth century. A common procedure was to fill the shell cavity with gunpowder or to put the explosive into a loosely-restrained bag at the base of the projectile. In this latter variation, when the projectile struck the target it was intended that the bag would be torn loose from its restraints and flung forward against the interior of the shell. In either variation, these projectiles relied upon impact shock to set off the burster. About as reliable as it sounds, hence the intensive search for better explosives, more reliable fuzing and the interest in the Zalinsky "Dynamite Gun" experiments.

Composition A - USN burster made from a mixture of 91% RDX and 9% wax. In use near the end of World War II in a few AA projectiles.

Composition Exploding or CE - See "Tetryl" below.

Gun Cotton - See "Propellants" below.

Explosive D - USN burster made from "Dunnite" which is Ammonium Picrate, a salt formed from picric acid. Named after its inventor, Lieut.-Col. B. W. Dunn (1860 - 1936) US Army. Adopted by the US Navy in 1911, this explosive is very insensitive to shock, giving it a high margin of safety. This burster was used for almost all USN projectiles until long after World War II.

HMn - Hydrazine Mononitrate. Most commonly used as a rocket fuel, but also used by the French Navy as a burster in a few projectiles.

Pentolite - A mixture of TNT and PETN, usually 50/50. This was not as stable as TNT in storage. Used in some USN 20 mm ammunition during World War II.

Picric Acid - A trinitrated derivative of phenol or trinitrophenol. Invented by the German chemist Hermann Sprengel and patented in 1885 by the French chemist Eugène Turpin in pressed and cast form for use in blasting charges and artillery shells. Picric acid is a powerful explosive but its strong acidity causes it to combine with iron in projectiles.

Ecrasite - Austria-Hungary picric acid.

Lyddite - British picric acid, trinitrophenol. Prior to 1908, the British used gunpowder as the burster for both AP and Common shells, but after that date Lyddite came into use for HE projectiles. In 1909, the Royal Navy began experimenting with APC using Lyddite as the burster and began introducing them into service the following year, even though testing had shown that this filling was more sensitive to shock than gunpowder and thus prone to explode prematurely before the shell had a chance to penetrate almost any thickness of armor plate.

Shimose - Japanese picric acid. Named after its inventor, Shimose Masachika (also spelled as Shimose Masakazu), but there is some evidence that it was actually based upon a sample of Melinite brought back from France. Adopted on 17 February 1893. Also known as PA bakuyaku (picric acid explosive).

Shellite - British burster adopted just after the end of World War I, this was a less sensitive picric acid mixture, containing a mixture of 70% Lyddite and 30% of the much weaker, insensitive explosive dinitrophenol.

Tetryl - Trinitrophenylmethylnitramine. A sensitive, high power burster. Tetryl is a light yellow crystalline material and was first made in 1877. Known in the British Royal Navy as Composition Exploding or CE.

TNA - Japanese tri-nitro-aniso, designated as Type 91 bakuyaku (Model 1931 Explosive). Adopted on 25 July 1931, this was a methylated derivative of picric acid and a more stable burster than Shimose.

TNT - Tri-nitro-toulene. Few, if any, nations used pure TNT. Instead, this was usually mixed with a desensitizer, such as beeswax. For example, German shells of World War II used a beeswax mixture with the concentration of beeswax decreasing from the head to the base of the cavity.

Bursting Charge Power - The following approximations of explosive power may be used using TNT = 1.00 as a reference point.

Other Explosives (torpedo warheads, mines, depth charges)

DD (Dinitronaphthalene/Dinitrophenol 60/40) = 0.82

MDN (Melinite/Dinitronaphthalene 80/20) = 0.88

Japanese Type 97 (TNT/hexanitrodiphenylamine 60/40) = about 1.07

Two rules of thumb about Burster Power

1) The effect of the burster may be taken as being proportional to the square root of the weight of the bursting charge.

2) For the same basic shell design, the size of the bursting charge is proportional to the cube of the bore size.

Ammonium nitrate (AN + <0.5% H2O)

Black powder (75% KNO3 + 19% C + 6% S)

Tanerit Simply® (93% granulated AN + 6% red P + 1% C)

Tovex® Extra (AN water gel) commercial product

Hydromite® 600 (AN water emulsion) commercial product

ANNMAL (66% AN + 25% NM + 5% Al + 3% C + 1% TETA)

Tritonal (80% TNT + 20% aluminium)*

Nitrocellulose (13.5% N, NC; AKA guncotton)

PBXW-126 (22% NTO, 20% RDX, 20% AP, 26% Al, 12% PU’s system)*

Diethylene glycol dinitrate (DEGDN)

PBXIH-135 EB (42% HMX, 33% Al, 25% PCP-TMETN’s system)*

PBXN-109 (64% RDX, 20% Al, 16% HTPB’s system)*

Dynamite, Nobel's (75% NG + 23% diatomite)

Torpex (aka HBX, 41% RDX + 40% TNT + 18% Al + 1% wax)*

Composition B (63% RDX + 36% TNT + 1% wax)

Pentolite (56% PETN + 44% TNT)

Semtex 1A (76% PETN + 6% RDX)

RISAL P (50% IPN + 28% RDX + 15% Al + 4% Mg + 1% Zr + 2% NC)*

Mixture: 24% nitrobenzene + 76% TNM

Mixture: 30% nitrobenzene + 70% nitrogen tetroxide

Octol (80% HMX + 19% TNT + 1% DNT)

DADNE (1,1-diamino-2,2-dinitroethene, FOX-7)

Gelignite (92% NG + 7% nitrocellulose)