An Introduction to Collecting Artillery Shells and Shell Casings

by Andrew Duguid 

Questions or comments can e-mailed to the author at big_ordnance@hotmail.com.


!!!WARNING!!!

LIVE ARTILLERY SHELLS OR COMPONENTS
MAY BE VERY DANGEROUS. IF YOU THINK YOU HAVE 
A LIVE SHELL OR ARE UNSURE IF YOU HAVE A LIVE SHELL,
DO NOT TRY TO DISARM IT YOURSELF. THAT MAY KILL YOU.  
NOTIFY THE PROPER AUTHORITIES (POLICE OR BOMB SQUAD).

 

NOTE: Click on images to view larger size.

    The different roles that artillery ammunition has had to fill on the battlefield has led to many different designs and types of ammunition, some of which are discussed here  And while artillery has been used by armies for hundreds of years, this article focuses on "modern" ammunition (post-1870).  (The ammunition pictured in the article was used by the United States unless otherwise noted.

A complete round of artillery ammunition, with the exception of blank ammunition, always consists of a projectile, propellant, and a primer. The propellant can either be blackpowder or smokeless powder in the form of cylindrical grains of various sizes. The propellant is packed into a shell casing or a combustible bag (a powder bag). Depending on how the propellant is loaded into the gun with the projectile, artillery ammunition is classified into four groups: fixed, semi-fixed, separated, and separate loading.

  • A fixed round of ammunition has shell casing that is crimped (fixed) to the projectile. 

  • With semifixed ammunition, the casing and the projectile still fit together,  but the shell casing can be removed to adjust the size of the powder charge.

  • With separated ammunition, the shell casing is not attached to the projectile at all.  Normally, the shell casing for separated ammunition is closed with a plug to protect the propellant and assist with pushing the projectile into the chamber of the gun.

  With most fixed, semifixed, and separated rounds of ammunition, the shell casing contains the primer. 

  • Separate loading ammunition is made up of a projectile, a powder bag or other separate charge, and a primer. 

Figure 1 shows each type of ammunition

Figure 1 Different types of artillery rounds.

Shell Casings

    Shell casings come in a wide variety of sizes, shapes, and materials.  Shell casings are normally described according to the diameter of the mouth in millimeters (mm), the length of the casing in mm, and the design of the rim.  For example, the US 37mm casing used in WWII era tank and antitank guns is a 37 x 223R, where R stands for rimmed. 

    A shell casing may have several different styles of bases (heads). The most common ones are rimmed, semirimmed, rimless, rebated, and belted.

  • Rimmed casings have a rim at the base of the shell casing; the rim is wider than the rest of the shell casing.  Rimmed casings are denoted by the suffix R after the diameter and length. 

  • Semirimmed casings also have a rim that is wider than the body of the casing, but just above the rim there is an extraction groove.  Semirimmed casings are denoted by the suffix SR.

  • Rimless casings have no suffix that follows the diameter and length.  

  • Rebated casings have a rim that is actually smaller that the body of the casing. Like semirimmed casings, they too have an extraction groove just above the rim.  Rebated casings are denoted by the suffix RB. 

  • Belted casings have a belt of metal above the extraction groove. The belt is approximately the same diameter as the rim. These casings are denoted by the suffix B.

Figure 2 shows the most common rim styles.

Figure 2 Common rim styles on artillery shell casings.  Left to right: Rimmed (90 caliber gatling [23x107R]), semirimmed (1.1-inch antiaircraft [28x199SR]), rimmless (20mm Hispano [20x110]), rebated (20mm oerlikon [20x110RB]), and belted (27mm Olin experimental [27x70B]).

    Shell casings have been made from many different materials including brass, steel, aluminum, plastic, and combustible materials.  They may also be made from a combination of these materials.  Many casing have special finishes on their surfaces to protect them from harsh conditions.  Brass casings normally have no finish. Steel casings are normally painted, lacquered, copper washed, or finished with zinc chromate to keep them from rusting.  Aluminum casings are typically anodized but may also be unfinished.  Anodized casings can come in a variety of colors including red, orange, gold, green, brown, blue, and purple etc.  Combustible casings are normally waterproofed to keep them from getting damaged by moisture.  Figure 3 shows examples of casings made from different materials.

   

Figure 3 From left to right:  Brass (4-inch 50-caliber shell casing [102x884R] {1918}), plastic and aluminum (experimental 30mm used in Philco-Ford's submission to the GAU-8 competition [30x167] {1970s}),painted steel (US 25mm steel casing used in the AV8 harrier jet [25x137] {1983}), lacquered steel (37mm T68B2 shell casing for the Vigilante AA system [37x219] {1950s}), chromate steel (105mm howitzer casing [105x372R] {1950s}), anodized aluminum (30mm WECOM [30x100B] {1960s}), anodized aluminum (30mm casing for GAU-8 cannon [30x173] {1989}), steel and combustible (120mm TP-T round for the M1A1 tank {Current}).

    Typically artillery shell casings are manufactured in the same way as small arms shell casings, by drawing them out from a cup or a disc of metal (Figure 4).  Drawing is probably the most common method of constructing casings. However, metal casings have also been constructed by riveting or fastening the head to a coil of sheet metal that forms the body (Figure 5).  Winchester used a combination of drawing and riveting to construct shell casings in the late 1880s and 1890s (Figure 5).  These casings had a have drawn walls and a two-piece head that is attached with rivets.  Plastic casings are normally injection molded (Figure 6).

Figure 4  Draw steps for the 20x110 Hispano casing.

    

Figure 5 Coiled and non-coiled multipiece casings.  From left to right:  Photos 1 and 2 show the side and base of a coiled, three-piece, 37mm Hotchkiss [37x94R] {1884} casing; note the three rivets holding the casing together.  Photos 3, 4, and 5 show a non-coiled, three-piece Winchester 6-pounder [57x306R] {1889}. The arrows in the photo of the base of the casing point to the rivets that hold the casing together.

Figure 6 Unfinished injection-molded component (right) and sectioned plastic and metal shell casing (left) [20x102] casing by AAI. 

    Most shell casings have only one opening, at the mouth for the projectile. However, some shell casings have a large hole on the base or many holes on the side.  These casing are for recoilless weapons.  Recoilless weapons balance the force of the projectile leaving the gun barrel with an equal force from gas leaving the rear of the gun.  To allow the blast to leave the back of the gun, some of the gas from the burning propellant is directed either out the bottom or side of the shell casing and out the back of the gun.  Recoilless casings that allow gas to pass through the base are normally closed with a fiber base.  The casings that allow gas to pass through their walls are lined with a combustible liner to hold the propellant and protect it from moisture. The primers in recoilless cases are in the center of the base for the casings with perforated sides and are in the base or on the sides for casings with blow-out bottoms.  Figure 7 shows examples of recoilless shell casings.

      

Figure 7 Recoilless shell casings. From left to right:  Experimental 6-pounder Davis recoilless with primer on the side {Pre WWI}, base of the 6-pounder Davis showing the notch to line it up in the gun, 90mm recoilless [90X397R] {1960s-1970s} with fiber base and primer in the base, 106mm recoilless shell casing [105x607R] {1950s-1970s}.

    Often a collector encounters shell casings that have been altered.  Sometimes alterations are legitimate military alterations made for experiments (Figure 8); sometimes the casings are altered to make blanks (Figure 9); and sometimes they have been altered to make "trench art" such as umbrella stands, pencil holders, vases, and lamps (Figure 10).

Experiments that alter casings usually change the length of the casing, the style of the rim, or the diameter of the mouth.  Sometimes these altered casings are marked to reflect the changes, but sometimes they are not.  Although they are not always marked, they are usually well made, and so it is clear that they are legitimate shell casings and not just made by someone fooling around.  

Blanks are often made from shell casings by cutting the shell casing down. It is not normally necessary for a blank to contain as much powder as an actual round.  Blank shell casings are usually marked "blank" or "saluting," the word either stamped on the head or stenciled on the head or the side. Sometimes it can be hard to tell if a cut-off casing is a blank if it is not marked.  You know it is not a blank if the edge at the mouth is rough or uneven or shows saw marks. 

 

Figure 8 Shell casings altered for testing and their unaltered counterparts. From left to right: 1.1-inch AA shell casing [28x199SR] {1930s-WW2}, 20mm made from a 1.1-inch AA shell casing [20x199SR], 25mm PGU 25 [25x137] {Current}, and 20mm made from a 25x137 [20x137].

Figure 9 Full length 6-pounder shell casing [57x306R] {1890s-WWI} (left) and cut down blank {WW2} (right).

Figure 10 Damaged casings: Cut off British (left) and German (right) shell casings.

Projectiles

    There are many different types of projectiles that a collector may encounter, including explosive shells, antiarmor projectiles, target practice projectiles, chemical shells, canister shot, cargo shells, illumination shells, proof shot, and dummy rounds.  Projectiles that explode, carry chemicals, or carry other payloads are called shells.  Projectiles that are completely solid or do not explode are sometimes called shot.  Most modern projectiles have many features in common. These features include a fuze, ogive, bourrelet, and rotating band (Figure 11). 

Figure 11 Diagram identifying different sections of a projectile.

Fuze

    Fuzes are used on a projectile to initiate detonation or cause the projectile to function.  Fuzes may be used in the nose or the base of the projectile (or both).  A further section shows examples of different fuzes. 

Ogive

    The ogive is the curved part of the projectile that starts at the point and ends where the projectile becomes cylindrical.

Rotating band

    A rotating band is a metal or plastic band that serves to engage the rifling on the gun and trap propellant gases at the rear of the projectile.  Engaging the rifling imparts a spin on the projectile, and the spin stabilizes the projectile while it is in flight.  Rotating bands may be made out of many different materials including brass, copper, iron, and plastic (Figure 12).  There are many different designs of rotating bands: Some are solid, and some have grooves (Figure 13).  Some projectiles have multiple driving bands (Figure 13). 

    Projectiles that are not stabilized by a rotation are typically stabilized by drag.  The drag is usually caused by fins although sometimes a cone may be used.  Sometimes a fin-stabilized projectile may have a rotating band.  These rotating bands are added just to trap propellant gases behind the projectile.  If the finned projectile is being fired from a rifled gun, the rotating band will be free to rotate on the projectile so that no spin from the rifling will be imparted on the projectile.  Figure 14 shows fin and cone stabilizers for projectiles.    

   

Figure 12  Rotating bands made from different materials.  From left to right: Copper, brass, iron, and plastic.

 

Figure 13 Single rotating bands with and without grooves (left) and multiple rotating bands (left).

Figure 14  Cone stabilization (left) and fin stabilization (right).

Bourrelet

    Some projectiles also have a bourrelet.  A bourrelet is a section of the shell that is machined so that it rides on the lands of the rifling.  The bourrelet keeps the shell from wobbling in the gun barrel. 

Tracer

    Many projectiles have a tracer--a pyrotechnic pellet on the rear of the projectile (Figure 15).  When the projectile is fired, the tracer is ignited by the burning propellant.  Tracers are used to observe where the projectiles are going.  To signify that a round is a tracer, a "-T"  is added to its nomenclature.  For example, an armor piercing (AP) round with a tracer is an AP-T.

 

Figure 15 Tracer cavities (tracer compound has been removed).

Explosive Shells

    Explosive shells are used to destroy soft targets and inflict causalities.  Explosive shells may be fuzed in the nose, in the base, or both.  Early shells are often referred to as "common shells," the reason being, according to the book United States Artillery Ammunition, that they were made of common steel.  However, according to The Illustrated Encyclopedia of Ammunition, they are called common shells because they were the common shell used against all targets.  The explosive used in early shells was black powder, a low explosive.  Figure 16 shows nosed-fused shells used in 1880s and 1890s era Hotchkiss revolving cannons.  Figure 17 shows base-fuzed common shells from the 1880s through the 1920s.

Figure 16  1870s and 1880s era nose-fused shells for Hotchkiss revolving cannons.  From left to right:  37mm, 47mm, and 53mm.

Figure 17  Base-fuzed common shells from left to right: 1.65-inch Hotchkiss {1890s-1900s}, 3-pounder (47mm) {1890s}, and 3-inch field gun {WWI}.

From the early 1900s to the present, more powerful high explosives (HE) have been used in explosive shells (Figure 18).     

 

Figure 18  High-explosive shells.  Left:  Nose-fuzed 105mm M1 HE {WW2}. Right: Base-fuzed 37mm M63 HE {WW2}.

Armor Piercing and Antitank Projectiles

    Armor piercing projectiles are used to destroy armored vehicles or other hard targets.  There are two broad categories of armor piercing projectiles.  One category uses mass and velocity (kinetic energy) to pierce the target.  The other category uses explosives.  Kinetic energy projectiles pierce by placing more stress on the target than the target can withstand.  Kinetic energy antiarmor projectiles consist of the following types:

KINETIC ENERGY ANTIARMOR PROJECTILES

Armor piercing (AP)

    An AP projectile is a hardened-steel projectile. AP projectiles may have a small cavity in the base for explosive, or they may be solid.  AP projectiles look a lot like base-fuzed common shells, but they are made from much harder steel.  Also, the cavity in the base for explosive, it is much smaller than that of a common shell.  Figure 19 shows a diagram and a photo of an AP shot.  

 

Figure 19  AP projectiles: Diagram (left) and 37mm M74 shot {WW2} (right).

Ballistic capped AP projectiles.   

    Ballistic-capped AP projectiles are AP projectiles with the addition of an aerodynamic ballistic cap (a windshield).  A more aerodynamic projectile means the projectile hits the target with a higher velocity and therefore more force than a nonballistically capped projectile.  Therefore the projectile is able to apply a greater stress on the target and stands a greater chance of defeating it.  Figure 20 shows a diagram and a photo of a ballistical-capped AP projectile.

 

Figure 20  Ballistic-capped AP projectile: schematic (left) and 120mm M358E1 {1960s} (right).

Armor piercing capped (APC)

    APCs are AP projectiles with a special soft-steel cap attached to the front of the projectile (Figure 21).  The cap keeps the hard-steel projectile body from cracking when it hits the target, thereby increasing the effectiveness of the projectile.

 

Figure 21 APC projectile: schematic (left) and 37mm M59 projectile {WW2} (right). 

Armor piercing capped ballistic capped (APCBC)

    APCBCs are APC projectiles (Figure 22) with the addition of a windshield to improve the aerodynamics of the projectile.  The U.S. calls APCBC projectiles APC projectiles.

 

Figure 22  APCBC projectiles.  From left to right:  Diagram of a base-fuzed explosive projectile and nonexplosive projectile, MK29 APCBC projectile {WW2}.  

Hyper velocity armor piercing (HVAP)

    HVAP projectiles are made using a relatively light, usually aluminum, body to enclose a hardened-steel, tungsten, or depleted uranium core.  This type of projectile relies on the core to defeat the target.  Because the core is much smaller in diameter than the projectile and contains most of the mass of the projectile, it is able to apply a larger stress on the target than an AP projectile of the total diameter.  Figure 23 shows a schematic and a photo of a typical HVAP projectile.  A  British term for HVAP projectiles is armor piercing composite, rigid (APCR).  One unusual-looking HVAP type of projectile is the arrowhead shot (Figure 24).  Arrowhead shot are called that because the projectiles resemble an arrowhead.  They were used by the Soviet Union and Germany in World War Two.  

 

Figure 23  HVAP projectile: Schematic (left) and 90mm M304 {1947} (right).

Figure 24  Diagram of a German arrowhead shot.

Armor piercing discarding sabot (APDS)

    APDS projectiles are similar to HVAP projectiles in that they rely on a hard dense core to pierce the target.  However, in an APDS projectile the core is the only portion of the projectile that reaches the target.  The outer body of the projectile is shed after it leaves the muzzle of the gun, which thus leaves only the core to travel to the target.  By shedding the light outer portion of the projectile, the diameter of the projectile is made smaller without a large change in mass, which translates to a larger stress on the surface of the target when the core hits it.  The outer portion of the projectile that is left behind is called the sabot.  Sabots are typically either a cup type that is left behind in one piece or a petal type that breaks up into multiple pieces (petals) after leaving the gun.  Figure 25 shows several APDS projectiles.  

  

Figure 25  APDS projectiles:  76mm M331A2 {1950s} (left) with a cup-type sabot and 25mm M791 with petal-type sabots {1990s}.  Also shown in the right photo are three APDS cores and two bases for 25mm projectiles. . 

Armor piercing fin stabilized discarding sabot (APFSDS).  

    APFSDS projectiles are an improvement on the APDS.  The fin stabilization allows for a longer core than that of the APDS projectiles, and the longer core means more mass.  Because the core has more mass, it can produce more stress when it hits the target and so it is more likely to defeat it.  The sabots for APFSDS projectiles are typically petal-type sabots.  APFSDS are sometimes called fin-stabilized armor piercing discarding sabot (FSAPDS) projectiles.  Figure 26 shows different APFSDS projectiles.

   

Figure 26 APFSDS projectiles:  30mm APFSDS {Current}, sectioned 40mm PGU 31/B {1987}, sectioned 105mm M833 {1980s-1990s}, and 105mm M735 without sabot {1970s-1990s}. Note: The grooves around the bodies of the dart-like core of the projectile ensure the sabot has good contact as the projectile travels down the gun barrel.

EXPLOSIVE ANTIARMOR PROJECTILES

 
 

    Two types of projectiles use explosives to defeat hard targets: high-explosive antitank (HEAT) and high-explosive plastic (HEP).    

HEAT projectiles

    HEAT projectiles use a shaped charge to defeat armor.  A shaped charge, also called a hollow charge, is a cone with its tip pointing to the rear of the projectile that has explosives packed behind it.  When the explosives are initiated, the cone is inverted and turned onto a jet of molten metal and gas that punches a hole in the target.  Early HEAT projectiles pre WW2 into the 1960s were spin stabilized.  However the rotation of the projectile reduces the effectiveness of the shaped charge, so most HEAT projectiles that have been adopted since the 1960s have been fin stabilized.  Figure 27 shows different HEAT projectiles.

   

Figure 27  HEAT projectiles: Diagram of a spin-stabilized HEAT projectile, M66 75mm spin-stabilized HEAT round {WW2}, diagram of a fin-stabilized HEAT projectile, 105mm M456 fin-stabilized HEAT round {1970s-1980s}.

    HEP projectiles (Figure 28) are also called high-explosive squash head (HESH) projectiles.  HEP projectiles deform when they hit the target: The nose flattens against the wall of the target, and then the explosives detonate.  The explosion causes material from the inside of the target to be blown off, creating lethal fragments within the target.   

Figure 28  106mm recoilless rifle M346A1 HEP projectile {1960s}.

Target Practice Projectiles

    Target practice (TP) projectiles come in the same shapes and weights as tactical projectiles.  The reason for this is that TP projectiles must match the ballistics of the tactical round so troops can learn to hit their targets.  Figure 29 shows different TP projectiles.

   

Figure 29  TP projectiles from left to right:  105mm M490 TP projectile {1970s-1980s} (TP version of the 105mm M456 HEAT projectile), 16-inch MK15 TP projectile {1937} (TP version of the MK13 high-capacity shell), 90mm M317 TP projectile {1950s} (TP version of the M304 HVAP projectile), and 120mm M865 target practice cone-stabilized discarding sabot (TPCSDS) projectile {1989}.  Note: The M865 is cone stabilized to reduce its maximum range to keep it from impacting far from the practice ranges; the tactical version is fin stabilized.

Canister Shot

    Canister shot are used for antipersonnel purposes. They act like large shotgun shells.  A canister projectile is a hollow metal projectile that is full of smaller projectiles.  Early projectiles used lead balls as their load.  Later projectiles used steel balls, steel pellets, or flechettes (small darts).  When the canister leaves the muzzle of the gun, the canister breaks apart, releasing its contents.  Figure 30 shows different canister projectiles. 

  

Figure 30  Canister shot.  From left to right:  6-pounder sectioned to show lead balls {1880s}, 37mm M2 canister for tank and antitank guns loaded with steel balls {WW2}, 90mm recoilless XM590E1 canister loaded with flechettes {1960s}.

Shrapnel Shells

    Shrapnel shells are another form of antipersonnel shells.  They were first developed by Henry Shrapnel in the 1780s and were originally called case shot.  Shrapnel shells were phased out of use by most countries by the end of WW2.  Modern (post-1900) shrapnel shells are are filled with lead balls in a matrix of resin.  The lead balls are called shrapnel (fragments from any other type of shell are shell fragments, not shrapnel).  The shells are time fuzed and have an expelling charge that causes the balls to be expelled out the front of the shell above the target.  The balls then spread out and hit the target.  Figure 31 shows a photo of a shrapnel shell and a diagram of how they work.

 

Figure 31  3.8-inch shrapnel shell (left) {WWI} and diagram showing how a shrapnel shell functions (right).

Antipersonnel Shells

    Antipersonnel shells, or APERS shells, are an improvement on shrapnel shells loaded with flechettes instead of lead balls.  When the shell explodes, thousands of flechettes are forced out of the front, creating a lethal hail of little darts.  APERS shells can be set to go off just after leaving the muzzle of the gun or at a specified distance by turning the dial on the time fuze in the nose of the projectile.  Figure 32 shows a diagram of an APERS shell.

Figure 32  Diagram of a 105mm APERS shell.

Chemical Shells

    Chemical shells include smoke shells, teargas shells, and poison gas shells.  Typically chemical shells are the same shapes as explosive shells.  However, chemical shells tend to have thinner walls.  They also, typically, have a central tube containing a bursting charge that is surrounded by the chemical payload.  Smoke shells are used to provide smoke screens.  Smoke shells may be the burning type such as HC smoke shells or the bursting type such as white phosphorous (WP) smoke shells.  Gas shells may also be either burning or bursting types.  Teargas shells tend to be the burning type.  Poison gas shells are normally the bursting type.  Poison gas shells deliver poison to kill or incapacitate troops.  Early versions contained the actual poison gas as the payload; later shells contain two separate nonpoisonous chemicals that are mixed upon the functioning of the shell and create a poison.  Figure 33 shows US WWI period markings for chemical shells.  Figure 34 shows photos of chemical shells.

 

 

Figure 33  US WWI period chemical shell markings.

Cargo Shells

    Cargo shells (Figure 35) are used to deliver submunitions or sensors to a target.  Submunitions (Figure 36) typically tend to be antipersonnel grenades, antimaterial grenades, antipersonnel mines, or antitank mines.  The shells look a lot like explosive shells.  The shells deliver their load when a time fuze in the nose sets off an expelling charge that expels the submunitions from the rear of the shell.

 

Figure 35  Cargo shells: 105mm Howitzer M915 sectioned to show M80 submunition grenades {1990s} (left) and 155mm Howitzer M741 shell used to deliver antitank mines {1992}.

   

Figure 36  Artillery shell submunitions.  From left to right:  M36 antipersonnel grenade used in the 105mm howitzer M444 shell {1970s-1990s}, M80 antimaterial/antipersonnel grenade used in the 105mm howitzer M915 and M916 shells {1980s-Current}, and M67/M72 antipersonnell mine used in the 155mm howitzer M692 and M731 shells {1970s-Current}.

Dummy

    Dummy or drill projectiles are used by troops to practice handling ammunition and practice loading and unloading weapons.  They come in the same calibers as tactical ammunition and may be made from wood, bronze, steel, or plastic.  Figure 37 shows some typical dummy rounds.

  

Figure 37  Dummy and drill ammunition.  From left to right:  3-inch 50-caliber MK7 drill cartridge {WW2}, 5-inch 38-caliber drill round (casing section only) {WW2}, 155mm howitzer M2 dummy projectile {WW2}.

Proof Projectiles

    Proof projectiles are used to ensure that weapons are strong enough to be accepted into service.  They are typically heavy, solid, blunt-nosed projectiles.  Figure 38 shows two different proof projectiles.    

 

Figure 38 Proof projectiles:  120mm for the M1A1 tank {1982} (left) and 75mm T-11 projectile for the 75mm fieldgun {WW2}.

Illumination Projectiles

    Illumination shells, sometimes called star shells, are used provide illumination to troops on the ground.  They are also used for signaling.  Typical illumination shells are nose-fuzed with an expelling charge just below the fuze that ejects the illumination candle out of the base of the shell.  Figure 39 shows an example of an illumination shell.  

 

Figure 39  5-inch 38-caliber MK30 illumination shell {WW2}:  Outside of shell (left) and inside of shell (right).  Note: The parachute that slows the descent of the illumination candle is missing.  It belongs below the candle at the bottom of the shell.

Fuzes

    Most shells need a fuze to function.  Fuzes may be in the nose or the base of the shell and may cause the shell to function on impact or after a certain amount of time, some distance from the target.

Point detonating

    Point-detonating fuzes (PDF) are used in the front of a projectile.  They cause the shell to function at or very shortly after impact. PDFs may be used in explosive and chemical shells. Figure 40 shows several PDFs.

  

Figure 40  Point detonating fuzes for 75mm and larger shells.  From left to right: MKV {WWI},  M48 series {WW2}, and M78A1 {WW2}.

Base Detonating Fuzes

    Base-detonating fuzes also cause shells to function upon or shortly after impact.  Base-detonating fuzes are used in the base of the projectile.  They are typically used in armor piercing projectiles, common shells, HEP shells, and HEAT shells.  Figure 41 shows typical base-detonating fuzes.

     

Figure 41  Base detonating fuzes:  From left to right: 1-pounder (37mm) base fuze {Spanish-American War}, M66 base fuze used in 75mm, 76mm and 3-inch APCBC projectiles {WW2}, M534A1 base fuze for the 105mm M393A1 HEP shell {1960-1990}.

Time Fuzes

    Time fuzes cause a shell to function a specified amount of time after it is fired.  Time fuzes are used on most types of projectiles including explosive, chemical, APERS, shrapnel, and illumination shells. There are three types of time fuzes: powder train time fuzes, mechanical time fuzes, and electrical time fuzes.  Powder train time fuzes are the earliest type; they were used through WW2.  To set the time a fuze will burn, either a small hole is punched through the side of the fuze (Figure 42 far left) or a ring containing part of the powder train is turned (Figure 42).  Both types are ignited by the acceleration of being fired.      

    

Figure 42  Powder train time fuzes.  From left to right: 15-second time fuze {1898}, M1914-1915 31-second time fuze, sectioned and outside {WWI}, and M1907M 21-second time, sectioned and outside fuze {WWI}.  Note:  All of theses fuzes also contain components that cause detonation on imact.

    Mechanical time fuzes use a clockwork mechanism to keep time.  The time is set by turning the dial from safe to the desired length of time using a fuze setter.  Figure 43 shows some examples of mechanical time fuzes.

  

Figure 43  Mechanical time fuzes: MK25 mechanical time fuze, outside and sectioned view {ww2} and M564 mechanical time fuze {1980}.

    Electrical time fuzes are recent time fuzes.  They are typically used on cargo shells.  Figure 44 shows a schematic of an electrical time fuze.

Figure 44  Diagram of an M587 electrical time fuze.

Proximity fuzes

    Proximity fuzes, also called VT fuzes, are used when a shell needs to function above or near a target.  They were developed in the United Stated during WWII.  VT fuzes use radio waves or other radiation to detect their target and cause the fuze to function.  They look similar to time fuzes because there are time settings on the fuze.  However, the time settings on VT fuzes indicate the amount of time until the fuze starts searching for its target.  The nose section of a proximity fuze is typically made out of plastic to enable the radio or other waves to pass through it.

 

Figure 45  Proximity fuzes for large caliber shells.  Diagram of M732A2 proximity fuze (left) and T226B1/A proximity fuze (right) {1950s}.

References

I used the following references during the writing of this page.  It is hard to describe how important it is to have a library. Suffice it to say, if you want to be able to identify shells and shell casings, you need to have as many references as you can afford.

MANUALS

Technical Manual 9-1904, Ammunition Inspection Guide, The War Department, March 2, 1944 .

Technical Manual 9-1901, Artillery Ammunition, Department of the Army, September, 1950.

Technical Manual 9-1300-203, Artillery Ammunition, Department of the Army, April 1967.

Technical Manual 43-0001-28, Army Ammunition Data Sheets. Artillery Ammunition: Guns, Howitzers, Mortars, Recoilless Rifles, Grenade Launchers, and Artillery Fuzes (Federal Supply Class 1310, 1315, 1320, 1390), Department of the Army, December 31, 1986 .

Field Artillery Ammunition, U.S Army Field Artillery School , 1924.

Fuzes for Use in Mountain, Field, Siege, and Seacoast Projectiles and in Detonating Fuzes, Government Printing Office, June 2, 1917 .

Ordnance Publication 1666, German Explosive Ordnance , U.S. Navy Bureau of Ordnance, June 11, 1946 .

U.S. Navy Projectiles and Fuzes, U.S. Navy Bomb Disposal School , August 6, 1944 .

BOOKS

Hogg, Ian, The Illustrated Encyclopedia of Ammunition, Chrtwell Books Inc, Secaucus, New Jersey, 1985.

Viall, Ethan, United States Artillery Ammunition, McGraw Hill Book Company, New York ,1917.

WEBSITES

Big-Ordnance, www.big-ordnance.com.

Cannon, Machine Guns, and Ammunition, www.quarry.nildram.co.uk.