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General information of artillery pieces
and artillery shells





The artillery piece as a weapon
(a very simplified description)

The primary sources for this section were
- "Itsenäisen Suomen kenttätykit 1918 - 1995", by Col. Jyri Paulaharju, ISBN 951-25-0811-7


An artillery piece is a firearm just as a rifle. It operates on exploding gases created by the propellant charges. The barrel gives the projectile it's direction. After the projectile has left the barrel, it flies to the target unguided (today there are "smart" guidable projectiles developed to be fired by guns, but that was not the case in World War 2) . The effect of the projectile in the target is created by the mass of the projectile or the explosive charge in it.

When a firearm is fired, the propellant charge creates two forces in the barrel. First, there is the force that gives the projectile it's energy to fly, and a counter force of equal size. The counter force is called recoil. The firearms are generally divided into two groups, guns with recoil (rifles, pistols, cannons, howitzers etc.) and recoilless guns (bazooka, panzerschreck etc.) .

In guns with recoil, the end of the barrel is closed, so the recoil forces it backwards. In small weapons (rifles, pistols etc.) , the recoil is usually sufficiently countered by the weight of the weapon and by supporting it (against the shoulder of the user for example) . In guns (cannons etc.) the recoil is countered by the weight of the guns and the recoil system (guns without recoil system roll several meters backwards when fired) . In recoilless guns, the pressure of the propellant gases is released backwards eliminating the effect of recoil.

The barrel of the gun is usually rifled, forcing the projectile to spin, stabilizing the projectile. Mortars have usually smooth barrels, so the mortar projectiles have tail fins that stabilize the projectile in flight.

The calibre of a barrel

The caliber of the gun is determined by the diameter of the barrel (inside). It's usually represented in millimeters, mm.

A VERY simple schematic display of a gun

The length of the barrel is represented by Calibers (in other words, how many times longer is the barrel than it's diameter).

A weapon is gun (artillery piece) , if it's BIG. The minimum caliber of a gun is 20 mm, and it needs two men to operate it. The guns are divided into different groups by it's intended use (field guns, coastal guns, antiaircraft guns, antitank guns, naval guns etc.) .

The range of a gun is affected by its caliber and especially the length of the barrel. The longer the barrel is, the higher muzzle velocity is achieved. The size of the barrel is the largest single reason for the weight of the gun.

The caliber of the gun, and the length of the barrel is used to divide guns into different classes; cannons, howitzers and mortars. These classes are further divided into light, heavy and super heavy (Järeä in Finnish) pieces.
In Finland, the guns are classed as follows;

Light cannons, are guns with below 100 mm caliber and howitzers with below 150 mm caliber
Heavy cannons have a caliber of 100 mm - 122 mm, and heavy howitzers 150 mm - 200 mm
Super heavy cannons have a caliber over 150 mm and super heavy howitzers over 200 mm


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A schematic display of a cannon shell trajectory A cannon is usually a weapon, which has a barrel length of at least 20 calibers. The cannons have usually the maximum elevation of 45º, light guns before the 1930s had a usual maximum elevation of 20º. (Since 1930s, quite many light cannons had even higher elevation maximums, and today, even heavy pieces have higher elevation maximums.)
The longer barrels make the cannons heavier than howitzers, but gives them superior range (as it gives the projectile higher muzzle velocity) . The lower maximum elevation restricts their use in forested terrain, since the battery sites must be placed in the open or major wood cutting has to be done (making it easier to identify battery sites from the air) .

The cannons fire usually with a flatter trajectory than howitzers.


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A schematic display of a howitzer shell trajectory The howitzers have usually a barrel length between 12 - 20 calibers, making the howitzers lighter than cannons of the same caliber Howitzers have usually higher maximum elevations than cannons, and are more often fired with higher elevations. This makes howitzers more useful in forested, rough and hilly terrain.


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A schematic display of a mortar shell trajectory Mortars are simple artillery weapons. It includes a smooth bore barrel resting on a baseplate which in turn rests on the ground. The mortars have a barrel length under 12 calibers They fire only indirect fire in high angles, elevations ranging usually from 40º to 80º. As the barrel is smooth, the projectiles have tail fins to stabilize the flight.

The mortars are relatively light weapons as they are intended to operate on lower firing pressures than conventional artillery pieces (cannons and howitzers) and thus don't need as strong (heavy) barrels. This makes them extremely useful in rugged terrain and as infantry support weapons, as light (up to about 70 mm) and medium mortars (usually 81 or 82 mm) are man portable. The short barrel and lower firing pressure restricts the maximum ranges of mortars to much shorter than the ranges of other artillery pieces. It also makes them less accurate, but as the projectile is inserted by dropping down the barrel from the muzzle, the rate of fire is high. The simple construction of mortars makes them also relatively inexpensive compared to heavier cannons or howitzers.


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Artillery projectile


The primary sources for the following sections are
- emails from Colonel Jyri Paulaharju to the author.
- "Tykistömuseon 78 tykkiä", by Unto Partanen, ISBN-951-99934-4-4



Basic definitions and general data

A VERY simple outlay of a shell

All artillery pieces use/fire ammunition that is called a shell (or round). The shell itself has different parts, which generally are:

  • The cartridge case, which holds the propellant charge and the projectile.
        All artillery shells don't have cartridge cases, instead the projectile and the propellant charge are loaded "separately", inserting first the projectile and then the propellant charge.
  • The projectile, which is the part of the shell that is propelled into the target (which contains the explosive charge / filler)
  • The propellant charge, which propels the projectile.
        The separate loading, mentioned earlier, is used generally with large caliber guns as it gives the chance to reduce muzzle velocity of the projectile by increasing or decreasing the amount of the propellant charge, thus affecting the range.
  • The fuse, which detonates the explosive charge (or filler) inside the projectile.
  • The primer, which detonates the propellant charge


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Artillery projectile blast effect

The artillery projectile ( / shell / round) , that lands in the target, has many different ways to cause damage to the enemy in the target area.

The different possible damage (or effect) types are generally pressure, splinter, shock, concussion and psychological. The amount and type of the blast effect depend mostly on the shape, structure and the caliber of the projectile. The kinetic energy of the projectile (to say it simple; the higher the velocity of the projectile is at the moment of impact, the higher the kinetic energy) , the blast of the explosive filler (causing a pressure wave) , the splinters that fan out from the body of the projectile, and even the volume of sound of the blast, are all common ways in what the blast cause damage in the target.


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This is an attempt to display an exploding projectile
The directions of the fragmentation cones, and the rough amounts of the splinters in them
(Note that the "side cones" visible in this picture
are in fact a part of the same cone, spraying a belt
of splinters vertically from the axis of the shell)

Projectile fragmentation


In general, when the explosive filler blow up, the detonating wave converts the explosive filler to gases which in turn exerts extremely high pressure on the inner surface of the projectile. The projectile expands until the critical stress for failure is reached. As the projectile breaks apart, the shear and cleavage sends fragments/splinters flying with high velocity in (roughly) three separate fans. This is called fragmentation effect. These fans or cones are the "forward cone", the "side cone" and the "base spray" (backwards). The aperture of these cones, and the amount of the splinters in them, depend mostly on the shape of the projectile (the body of the projectile), and the shape of the explosive filler inside the projectile. The direction of the splinters are affected by the velocity and the speed of rotation at the moment when the projectile explodes.

Usually the majority of the splinters are in the side cone (roughly 80 % of the splinters) , and with the shells fired by cannons and howitzers, which have cylindrical projectiles, the aperture of the cone is usually between 40 - 50 degrees. The shells fired by mortars, are usually drop-shaped, giving the side cone an aperture of over 50 degrees.

The forward cone and the base spray usually amount some 20 % of the fragments released by the shell. The forward cone has usually more fragments than the base spray.

The reason for this uneven distribution of fragments, is in the shape of the projectile. The ogive (forward tip of the projectile) , and the rear end of the projectile don't splinter like the sides do. The splinters in the side cone are also smaller than the splinters in the forward cone and in the base spray.




Fragmentation directions

Shallow angle
(relatively flat trajectory,
usually fired by cannons and/or

Steep angle
(mortar, and in some cases a howitzer)

Side view
Side view

Top view

Top view

These simple drawings show the basic splinter directions.
Note that a large part of the splinters, fanning out from a low trajectory shell,
fly up into the air, while the mortar shell, usually coming in
from a considerably higher angle, has a better angle of spreading the splinters around.


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The crater


Generally speaking, the blast of the artillery projectile creates a crater (or a shell hole) , if it penetrates the soil, and explodes underneath the surface at an optimum depth. The blast throws up soil high into the air, from which a part scatters around the point of impact, while a part falls back into the crater and to the edges of the crater creating a small embankment surrounding the hole. The maximum depth, where this type of a crater will be formed is roughly 10 times the caliber, which is usually also the radius of the blast.

Of course, the soil is also a factor. It's obvious that the resulting crater in soft sand in different than it is in a hard and rocky terrain.


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Fragmentation ranges and crate sizes caused by different caliber rounds
(The drawings and figures are based on data supplied by Col. Jyri Paulaharju to the author.)


The crater sizes and fragmentation ranges, shown below, are meant to be only general examples of crater sizes and fragmentation ranges, when the ground is common dirt soil. There are large differences between different shell types and different calibers, in both fragmentation range and crater size. Note that the fragmentation effect/ranges are shorter in deep snow. This was especially the case with small caliber guns (75 & 76 mm) reducing their effectiveness considerably. Also, as the ground was frozen, the projectiles didn't penetrate the ground deep enough to blast as large craters as are shown below.


The x- and y-axis have small marks each representing one meter each. I've also added a dot into it to represent the size of the shell hole.

The dimensions of the crater of a 76 mm shell General fragmentation ranges of 75 - 76 mm shells
The dimensions of the crater of a 107 mm shell General fragmentation ranges of 105 - 122 mm shells
(Note that the smaller dot is the crater of the 107 mm shell,
while the bigger is the crater of the 122 mm shell)
The dimensions of the crater of a 122 mm shell
The dimensions of the crater of a 152 mm shell General fragmentation range of a  150 mm shell


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Effect of artillery
against "soft" (infantry) targets in a 100 m x 100 m area
(Chart and data, courtesy of Col. Jyri Paulaharju)


[ This diagram is based on Finnish wartime experience, and is more of a theoretical graph of artillery effectiveness than a graph which could be applied automatically to every situation. The graph is based on the assumption that the point of impact is centered in the target area, and the area is covered with an optimum pattern. This of course rarely (if ever) happens in real life. So the purpose of the graph is perhaps more to illustrate the impact that an accurate barrage(s) has on infantry. ]


Graph # 1 - the estimated casualties against unprotected infantry in prone positions (i.e. not in trenches)

Graph # 2 - the estimated casualties against infantry in entrenched positions, if the defensive works (nests, earth & soil bunker etc.) are 6 m² in size and a direct hit or a near miss destroys it, or if the straight sections of the trench are some 4 m in length.

  • An enemy that suffers casualties ranging from 0 - 20 % is considered to be "harassed"
  • An enemy that suffers casualties ranging from 20 - 50 % is considered to be "suppressed"
    (As a further note Finnish experience showed that even 17 % casualties are enough to efficiently suppress the enemy.)
  • An enemy that suffers casualties over 50 % is considered to be "destroyed" (Meaning that the enemy unit(s) has lost it's ability to operate efficiently. This can vary depending on training and psychological reasons.)

I'd like to emphasize that these "casualties" shown in this graph are suffered in relatively short time (within a few minutes) , so the graph doesn't mean that a unit that has suffered 25 % casualties e.g. in a week is "suppressed".
Also, this graph doesn't apply to Soviet artillery, as it used a different firing technique, and had a lower density of grenades in the target hectare.




Back to Artillery weapons in the Winter War


Artillery pieces of both sides

Finnish Artillery

Field guns (without recoil system)
Field guns (part I)
Field guns (part II)

Soviet Artillery

Soviet field guns


For questions about picture copyrights, see 'Sources' page

Copyright © 1999 - 2006 Sami H. E. Korhonen

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