What does 9 mm mean? Calibers of smoothbore hunting weapons

In relation to rifled weapons, caliber is a numerical expression of the diameter of the bore, measured between opposing fields, or (which happens much less often) rifling. Even less common is measuring the rifling and rifling field of the bore that are opposite to each other. In most countries, the caliber of a rifle is expressed in millimeters and fractions thereof (usually accurate to the second decimal place when written as a decimal).

In the UK and the USA, as well as in countries where the English system of measures is adopted, the caliber is indicated in fractions of an inch - in thousandths in the UK and in hundredths in the USA, and the written designations have a peculiar form - the decimal fraction is written as an integer with a dot in front ( for example, the caliber designation “three lines” is 0.3" = 7,"62 mm, looks like .30 or .300).

The caliber is also indicated in lines, the ratios are as follows: 1 "= 25.4 mm, 1 line = 2.54 mm; and in points: 1 inch = 10 lines = 100 points. Thus, the three-line SI rifle. Mosin has a caliber 3x2.54 = 7.62 mm, and the calibers of the three lines, .30, .300, 7.62 are equal to each other.Recently, in England and the USA there is no dot before the designation of calibers.

For example, US caliber 30 should be multiplied by 0.254, and English caliber 300 by 0.0254g. As a result, we obtain that US caliber 30 is equal to 30 x 0.254 = 7.62 mm, and English caliber 300 is equal to 300x0.0254 = 7, 62 mm. Similarly, caliber 410 corresponds to 10.41 mm.

In rifled weapons, the diameter of the bore is measured either by the rifling or by the margins. Therefore, the same caliber can be designated differently. Thus, the 9 mm caliber of the “Los” carbine is designated by the margins (9 mm), and the TOZ-55 “Bison” caliber is designated by the rifling (9.27 mm). The caliber of a 5.6 mm rifle is sometimes designated as 5.45 mm: the first is a change in caliber by rifling, the second by margin. The 7.62x53R three-line cartridge has a leading bullet diameter of 7.92 mm. In general, originally domestic cartridges The diameters of the leading parts of the bullet are larger than the caliber. The diameters of bullets for rifled weapons always exceed the diameters of the bores (for the possibility of cutting into the rifling and acquiring rotational motion). The excesses of bullet diameters over the diameters of the bores are far from the same, since they depend on many reasons (depth, shape and number of rifling, bullet hardness, length of its leading part, quality of gunpowder, and others).

It is clear that of the several numbers mentioned above, obtained from various measurements of the diameters of the bore of a rifled barrel, as well as the diameter of the bullet, only one will correspond to the designated caliber. Typically this number refers to one of the dimensions of the bore, so the designated caliber of rifle ammunition is essentially the caliber of the weapon for which the ammunition is intended. The actual dimensions of the bullets never correspond to the designated caliber. Only in cases where the caliber of a weapon is measured by rifling do the designated calibers of the weapon and the true diameters of the bullets turn out to be very close to each other, close, but still different. It should be added to the above that among the caliber designations there may be those that do not correspond to the size of either the weapon or the bullets. They are simply traditional and do not act as information about size, but as a symbol of a particular cartridge. As a result, a mixed designation system has been adopted in world practice, in which a given cartridge is designated as it was designated in the country that issued it.

Perhaps the only one prerequisite is the presence in the name or designation of the cartridge of information about its caliber. Typically, caliber designations in the inch system are not translated into millimeters, since they are often either approximate or conditional, being only a symbol of a given cartridge, and not a carrier of information about the true size of the caliber. So, when formally converting, for example, designation 38 into millimeters, the value obtained is 9.65 mm. But this is a non-existent caliber - a symbol. 38 is actually a 9 mm cartridge used in weapons with a true caliber of 8.83 mm. Perhaps only specialists know that the .38 Special revolver cartridge uses .357 caliber bullets." The main reason for the discrepancies, as mentioned above, is the measurement of the bore diameter - by rifling or by margin.

Strictly speaking, the caliber of a cartridge is the caliber of the weapon for which the cartridge is intended to be fired. The caliber of the bullet itself almost never coincides with that indicated in the name of the cartridge, since its diameter is always greater than the diameter of the gun barrel, measured “along the margins”. For most cartridges developed in Europe, their name includes the numerical value of the caliber in millimeters, and for cartridges created in the USA and England, the name indicates the caliber in hundredths or thousandths of an inch. Although there are exceptions to this rule. For example, the purely European cartridge .30R Blaser (.30 Air Blaser) received a typical Anglo-American designation, and in the name of the American cartridges 7 mm Remington Magnum (7 mm "Remington Magnum") and 7mm-08 Remington (7 mm-08 "Remington") 19 gauge is indicated according to European traditions - in millimeters.

In the name of European cartridges, in addition to the caliber in millimeters, the length of the cartridge case in millimeters and its type are usually indicated - 7x64, 7x65R, 7x57R. The letter R means the presence of a protruding edge - a flange. Often in catalogs they add the name of the developer company - 7x64 Brenneke, 7x65R Brenneke. The designation of Russian cartridges is also based on this principle, however, as mentioned above, in domestic cartridges the diameters of the leading parts of the bullet are larger than the caliber. So, our 7.62x39 mm cartridge is actually loaded with 7.87-7.92 mm bullets, with the exception of its variants produced in the USA, which use regular bullets with a diameter of .308, i.e. 7.62 mm.

A certain specificity is found in the designation of old large-caliber (big bore) English cartridges for smoky and smokeless powder. Since all of these cartridges were rimmed, the case type designation was not indicated. Thus, .450-3 1/4 Rigby denotes the caliber in thousandths of an inch (.450), the length of the case in inches (3 1/4) and the company that produced this cartridge and/or weapons for it.

The .577 Nitro Express cartridge (3"&2 3/4") had two loading options - in a 3-inch (76.2 mm) long case and in a 2 3/4-inch (67.7 mm) long case.

In the designation of American and English cartridges there is no information about the length of the cartridge case, and the numerical designation of the caliber is followed by the name of the developer: .375 A-Square, .300 Dakota, .300 Holland & Holland, .308 Winchester.

Caliber and name of the designer who created this cartridge. More often found in the designation of American cartridges. Thus, one of the most powerful hunting revolver cartridges is the .454 Casull (.454 “Casull”) created by Richard Casull, or the rifle .300 Jarrett (.300 “Jarrett”), developed by Kenneth Jarrett. The name of Weatherby's most famous cartridge, the .300 Weatherby Magnum (.300 Weatherby Magnum), contains both the name of the company and the surname of its developer, Roy Weatherby.

Double hyphenated designations are historically common in American cartridges. So, in the days of black powder (practically until 1890), in type designations .44-40, .45-70, the first number showed the nominal value of the caliber, and the second - the amount of black powder charge in grains (1 grain = 64.8 mg). However, the first American rifle cartridge for smokeless powder, .30-30, created in 1895, also retained this principle in its name. The most notable exception to this rule was the famous cartridge .30-06 Springfield (.30-06 "Springfield"), in the designation of which the numbers 06 indicate the date of its adoption by the US Army - 1906.

Most modern dual designations are due to the fact that a particular cartridge was created from an existing cartridge case. The creators of such ammunition are often single designers - enthusiasts who produce them in limited quantities for use in weapons of their own systems. (So-called "wildcat" cartridges). For example, the .25-06 is a cartridge with a nominal .25 caliber, created on the basis of a .30-06 cartridge case, compressed for a .257 diameter bullet. The .22-250 cartridge with a .22 caliber bullet is created on the basis of the .250 Savage (.250 Savage) cartridge case. The designation of the new cartridge .30-378 Weatherby (.30-378 "Weatherby") refers to another cartridge - .378 Weatherby (.378 "Weatherby"), the sleeve of which was used as the base.

When creating the 7mm-08 Remington cartridge (7mm-08 "Remington"), loaded with bullets with a diameter of .284, a recompressed .308 Winchester case (.308 "Winchester") was used.

England uses its own designation system for “converted” cartridges, which is completely opposite to the American one. If the American cartridge .338-.378 Weatherby Magnum has a caliber .338 and is created on the basis of a re-compressed cartridge case of the .378 Weatherby Magnum cartridge, then the British would call such a cartridge .378/.338. The English cartridge .500/.465 Nitro Express is a .465 caliber cartridge that uses a re-compressed .500 NE cartridge case, similarly the .500/416 designates a cartridge with a .416 Caliber bullet based on a .500 NE cartridge case. Express (Express) and Nitro Express (Humpo Express).

Some English cartridges have two versions of equipment: a less powerful one for black powder, intended for old guns, and a more powerful one with smokeless powder, designed for modern, more durable weapons. The latter variants are designated Express or Nitro Express, which indicates that such a cartridge throws a bullet as fast as the train of the same name rushes.

Particularly powerful cartridges that, when fired, develop excessively in the bore of a weapon high pressure powder gases, have the definition Magnum (“Magnum”) in their name: .222 Remington Magnum, .300 Winchester Magnum, .338 Lapua Magnum (.338 “Lapua Magnum”). Until the early 1980s, the word "magnum" was usually present in the designation of cartridges, especially American ones. Modern magnums and ultramagnums may not have these names, designers, but only assign figurative names to them (300 Pegasus) or their own names and initials (300 Jarret, 375 JRS).

Also, at present, it is already difficult to assert that the so-called “search” design of the sleeve is a prerequisite for including a cartridge in the magnum group with the assignment of the term “magnum”. Two other criteria play a significantly larger role - pressure and bullet speed. Some European high-velocity magnum cartridges have the letter 5 in their designation: 5.6x61SE, 6.5x68S, 8x68S.

Some designers give their cartridges fancy proper names, like .300 Pegasus, .338 Excalibur and .577 Tyrannosaur (cartridges by Arthur Alfin, A-Square), apparently wanting to emphasize their unique speed and power. Abbreviations in names. When writing to save space (especially when marking on case heads), abbreviations are often included in the designation of cartridges. For example, the name of the revolver cartridge .44 Remington Magnum (.44 "Remington Magnum"), due to its wide popularity and the absence of similar competing cartridges in production, is increasingly being shortened to .44 Magnum or simply .44 Mag. The names of well-known companies that are present in the official designation of the cartridge are also usually abbreviated: Winchester - Win, Remington - Rem, Weatherby - Wby.

As you can see, various notation systems are very arbitrary and therefore do not allow one to calculate the real capabilities of a cartridge based on its name. It happens that a large caliber cartridge with a long case, like the 9.3x72R, in fact turns out to be not at all as powerful as one might expect. The energy of its bullet at a distance of 100 m from the muzzle is three times lower than that of a bullet from a much smaller caliber .300 Weatherby Magnum cartridge (.300 Weatherby Magnum). The difference is about 3500 J, which is comparable to the muzzle energy of the .308 Winchester cartridge (.308 Winchester).

Over time, the concepts of “weapon caliber” and “cartridge caliber” became more comprehensive, expanding to the full designation of a cartridge. This is quite logical, since different models of weapons with barrels of the same caliber can, differing in the shape of the chamber, be designed to use completely different cartridges with cartridges of different sizes and shapes. Therefore, the purely digital designation of the caliber, without the additions usually accompanying it, is now used only in relation to the bullet itself. Instead of the vague formulation “hunting carbine of 7.62 mm caliber”, another, more accurate and informative one is increasingly being used - “carbine (or cartridge) of 7.62x51 caliber”.

As is known, cartridges of the same caliber, even with the same diameters of the leading parts of the bullets, but with sleeves of different sizes and shapes, with flanges or grooves near the bottom, are absolutely non-interchangeable. In addition to the discrepancy between the cartridges, the non-interchangeability of cartridges is associated with the amount and type of gunpowder. Thus, the amount of gunpowder determines the pressure of the powder gases at strictly defined values ​​of the weight and diameter of the outer part of the bullet, the diameters of the rifling and fields of a particular gun, and the material of the bullet shell. For example, the nitroglycerin spherical powder used in the 7.62x51 cartridge cannot be used to reload 7.62x53R cartridges. Nitroglycerin spherical powder in a 7.62x51 cartridge with a semi-jacketed bullet weighing 9.7 g raises the pressure of the powder gases when fired to 3400 kgf/cm2. If this charge is poured into a 7.62x53R case, which uses a bullet weighing 13 g, then the pressure will rise even higher and can destroy the weapon. Weapons chambered for 7.62x53R are designed for operating pressures no higher than 3150 kgf/cm2.

Hunters should be aware that bullets for the same caliber of rifled weapons are in many cases not interchangeable. So, the diameter of the barrel bore along the rifling is domestic weapons for the 7.62x51 cartridge is 7.83 mm, and for the 7.62x53R cartridge the diameter of the leading part of the semi-shell and combat bullets is 7.92 (the diameter of the bore along the rifling for this cartridge is also 7.92), that is, larger. If a 7.62x53R hunting semi-jacket or combat bullet is removed and inserted into a 7.62x51 cartridge, when fired, this will result in a sharp jump pressure, which in turn can lead to the destruction of the weapon. Considering that the semi-jacketed bullet of the 7.62x53 cartridge weighs 3.3 g more, then such a shot is life-threatening. Foreign manufacturers always indicate the bullet diameter.

Trofimov V.N., Trofimov A.V. “MODERN HUNTING AMMUNITION for rifled weapons. CASES, POWDER, CAPSULES, BULLETS, CARTRIDGES, BALLISTICS ELEMENTS"

The caliber of a weapon is considered to be the diameter of its barrel. However, diameter can be measured either by the bottom of the rifling or the margin, depending on the country. To indicate caliber, the actual diameter is often rounded for convenience. Currently, most countries in the world use the metric system, in which the caliber of weapons is measured in millimeters. For example, 7.65 mm (seven point sixty-five hundredths of a millimeter, or in simplified form - seven. sixty-five millimeters), 9 mm, 10 mm. But in the USA, Great Britain and Canada the inch (imperial) system of measures is used. Moreover, in the United States, the caliber of weapons and cartridges is measured in hundredths of an inch, and in the UK - in thousandths. Notations are written as a decimal fraction after a period. For example, .38, .45 in the USA, and .380, .455 in the UK. Although in the USA, quite popular cartridges for compact weapons 9mm Short are designated as .380 ACP. Typically, inch designations have some tolerance regarding the actual diameter. The caliber designation may be the same for different cartridges or weapons, but the diameter of the bore and bullet may vary. So caliber .22 can correspond to a diameter of 5.6 mm or 5.5 mm. The bullet diameters of the .357 Magnum and .38 Special cartridges differ by only 0.02 mm, that is, 9.12 mm and 9.14 mm, respectively. Another difference between caliber designations and bullet or bore diameter is the different measurement systems. In the USSR, the caliber was measured by the rifling fields, as a result, the caliber of the bullet for the Makarov pistol cartridge is designated as 9 mm, but the real diameter of the bullet is 9.25 mm. That is, if the caliber was then measured by rifling, then the designation would be 9.2 mm. In other countries with the metric system, caliber is measured by rifling. The 9mmParabellum cartridge bullet has a diameter of 9.03 mm. In various printed sources, inch caliber designations are sometimes confused with metric ones. For example, inexperienced journalists refer to the forty-five caliber as a “45 mm pistol”... The caliber of a weapon in many cases refers to a specific cartridge, and not the diameter of the bore. There is also a division into small - up to 6.5 mm, normal - from 6.5 mm to 8 mm and large - from 9 to 20 mm calibers.

Bullet caliber designation

In the metric system, a cartridge is designated by the caliber of the bullet and the length of the cartridge case. For example, 7.62x25 and 9x17. Orally, these designations are read as “seven point six two hundredths by twenty-five millimeters,” or simplified as “seven sixty two by twenty five.” The cartridge case can have either a cylindrical or conical shape. If the cartridge case has a protruding rim, the suffix R is added to its designation. Like a revolver 9x32R (.357 Magnum). In the case of a slightly protruding edge and the presence of a groove for the ejector, HR and sometimes SR are added to the designation. For example, the 7.65×17HR pistol cartridge, often designated without a suffix, or as 7.65mm Browning. Also, in many cases, an abbreviation is added to the cartridge designation. For example, 6.35mm Browning, 9mm Parabellum or .45 ACP (from Automatic Colt Pistol - “Colt automatic pistol”). In the USA and countries Western Europe Currently, the suffixes +P or +P+ can be added to the designation of a particular cartridge. They denote powerful cartridges loaded with an increased charge of gunpowder compared to the standard version of the equipment. With a more powerful powder charge, the maximum pressure in the barrel bore during firing, as well as the energy and initial speed of the bullet also increase. Moreover, the assignment of these suffixes is not regulated by any standards. There are only general ideas at the expense of maximum pressure. Thus, the +P suffix is ​​assigned to cartridges with a maximum pressure exceeding the standard by approximately 10%, and the +P+ suffix is ​​assigned to cartridges with a pressure exceeding the pressure by more than 10% and, generally, with an excess of up to 25%. Regardless of the designation, the most important element The cartridge is the bullet, or rather its design.

Choosing an Effective Weapon Caliber

The most important quality of any cartridge used for self-defense is the ability to stop an attacker as quickly as possible. Modern statistics show that shooting using short-barreled weapons is carried out in most cases at a distance not exceeding 6 - 7 meters. At this distance, the stopping effect of the bullet (abbr. ODP) is crucial, along with the ability to maximum speed fire a series of accurate shots. To a large extent, shooting efficiency is increased by the use of cartridges with modern expansion bullets, which increase the ODP from 20 to 25%. Speaking about the effectiveness of any bullets and preference for any of their types, it is necessary to briefly mention the sources of information. Unlike testing cartridges for personal short-barreled weapons on ballistic gelatin, the main supplier of the most important data on the effectiveness of certain bullets remains the use of weapons by police or civilians. Cartridges for a pistol or revolver are selected based on the bullet’s ability to stop an enemy in the shortest amount of time. Statistics and any data on the effectiveness of various cartridges in real shootings are the result of rigorous research, such as evidence collection, medical examination of victims' wounds or autopsies, ballistic examinations, interviews of participants and witnesses. The accumulated data allows us to get an idea of ​​how effective the cartridges used in service weapons will be and how much some will be preferable to others. The use of materials and data on the use of various cartridges by police also helps civilians licensed to own and carry short-barreled weapons to choose the best cartridges for their pistol or revolver.

Expansive bullet

An expansive bullet is deformed when it hits soft fabrics, significantly increasing its diameter.

This type of bullet is the most common in the civilian and police weapons market. At the same time, bullets that deform upon impact are prohibited for use in the armed forces by the Hague Convention, as they cause very serious injuries. By deforming, the hollow-point bullet also increases the diameter of the wound channel, accordingly increasing the damage caused and leading to a faster stop of the attacking enemy. Deformation is achieved by creating an expressive void in the head of the bullet. This recess is usually open, and the shell in the head part, as a rule, has several longitudinal grooves that serve to evenly divide the head part into separate elements, “petals,” during deformation. The hydrodynamic shock when a bullet hits the body of a person or animal causes the walls of the recess in the head of the bullet to expand and turn inside out. Hollow bullet designs sometimes use a cap to cover the expressive void. This is done to increase the reliability of chambering the cartridge from the magazine into the chamber and to prevent clogging of the void. When hit, the cap wedges the cavity of the head part, which leads to its further expansion. The execution of the most expressive void can be very different, with different diameters of the hole, different geometry, and different shapes of the edges of the shell in the head of the bullet. The main goals of improving the design of hollow-point bullets are stable expansion upon impact, regardless of whether the bullet previously penetrated a light obstacle or not, as well as a stable expansion diameter. The sharp edges of the elements of the deformed shell also cause additional damage. All this is necessary to stop the enemy as quickly as possible. Currently, ammunition manufacturers have come close to perfecting the design of hollow-point bullets, making them even more effective.

Jacket bullet

The jacketed bullet is the most common type of bullet.

This bullet has a very simple design, consisting of a core and a shell. The core can be either solid or composite. The solid core is made primarily of lead. Composite, as a rule, has a steel core in a lead jacket. The core is located in a shell, which can also be made either from one material, for example, brass, or from two. For example, military bullets have jackets made of copper and tombac, called bimetallic. Jacket bullets have good penetration when hit and are generally not deformed. When using a steel core, such bullets are characterized by high penetration, which is necessary primarily in the armed forces. Sheathless bullets are a monolith made of lead, an alloy based on it, or, much less commonly, another material. Such bullets are currently most often used in small-caliber cartridges used in sporting pistols. These are the famous, extremely widespread .22LR (5.6 mm metric) cartridges, with a bullet diameter of 5.7 mm. In addition, non-jacketed bullets are used in revolver cartridges with low muzzle velocity. These are cartridges such as .45 Long Colt and .44 Special.

The caliber of the weapon is, along with the length of the barrel, one of the most important characteristics firearms, this fully applies to hunting smooth-bore weapons.

The caliber of a smoothbore hunting rifle refers to the diameter of its bore. The word caliber is of Arabic origin, derived from the word "galib", which means "shape".

Some hunters consider classic double-barreled shotguns with horizontal barrels to be the best shotguns, the most common among our hunters: IZH-54, IZH-58, .

Domestic semi-automatic machines are very popular. IN last years Foreign-made 12-gauge shotguns have become very popular and are gaining more and more popularity.

Both of these calibers are not intended for hunting, but are used for recreational shooting and self-defense purposes.

Which caliber is best for hunting?

All novice hunters, when purchasing their first gun, are interested in the question of which caliber to choose. Let us warn you right away that there is no clear answer to this question.

The choice of caliber depends on what game is intended to be hunted, in what way, and at what distance.

When choosing a caliber, hunters have strong personal preferences that outweigh any logical arguments in favor of a particular caliber. In any case, the choice should be reasonable; you should not go after a bear with a 410 caliber gun, this cannot end well.

In our opinion, the most correct caliber for a beginning hunter is 12. It is the most versatile. widely available in stores. Also, the choice of cartridges for it is the widest.

1. Definition
2. Methods and methods of measurement
3. The relationship between caliber and technical characteristics of weapons
4. The relationship between caliber and tactical characteristics of weapons
5. Effect of caliber on lethality weapons

Definition

Caliber is the diameter of the bore, as well as the diameter of the bullet.
The caliber of a cartridge is the caliber of its bullet.
Caliber determines the size, weight, power of weapons and ammunition.

Methods and methods of measurement

Methods for measuring weapon caliber:
- along the fields of the trunk;
- according to the rifling of the barrel.

Caliber determination methods:
. weight - its unit of measurement is 1 pound = 453.59 g and, accordingly, the number of bullets cast from metal of this mass.
Note: this method is used when measuring calibers of hunting shotguns.

Large caliber:

10 - 19.4 - 20.4 mm

Medium caliber:

12 - 18.2-18.7 mm
14 - 18.6-18.2 mm
16 - 17-17.25 mm
20 - 15.7-15.95 mm

Small caliber:

28 -14-14.25 mm
32 -12-12.75 mm

Linear - its unit of measurement is a line.
1 line = 2.54 mm; 1 point = 0.254 mm; 0.1 points = 0.0254 mm;
10 lines = 100 dots = 1 inch = 25.4 mm.
. numerical is a measurement of caliber in inches or millimeters.

Large caliber:
9 - 20 mm (for pistols and submachine guns from 9 to 15 mm);

Medium (normal) caliber:

6.5 - 8 mm (for pistols and submachine guns up to 9 mm);

Small caliber:
up to 6.5 mm.

Note: - caliber measurement in inches is typical for countries such as Great Britain, Canada, USA; - the designation of calibers remains the same as is customary at arms companies in the countries that manufacture weapons.

The relationship between caliber and technical characteristics of weapons

The caliber size is the basis for measuring the linear (longitudinal and transverse) parameters of the barrel and determines the type (class, type) of the weapon as a whole.
The barrel of a weapon consists of several parts:
- state-owned;
- average;
- muzzle.
Internal parts of the barrel:
- chamber (its length is determined by the length of the sleeve);
- bullet entrance (its length corresponds to 1-1.5 caliber sizes);
- threaded part.
Barrel length:
- for heavy machine guns - more than 70 caliber sizes;
- for rifles - approximately 70;
- for carbines - from 40 to 50;
- for pistols (submachine guns, revolvers) from 20 to 30.
The length of the section of the barrel in which the rifling of constant steepness makes one full revolution is called the pitch of the rifling.
Number of different shaped grooves:
- 4 (6) - with a caliber from 5.45 to 9 mm;
- 8 - from 12.7 to 14.5 mm;
- 12 - 30 (40) mm.

V beginning = T * L / 0.06 * D²/L - rifling pitch, in inches
V initial - initial bullet speed, ft/sec.
D - bullet diameter in inches
L - bullet length in inches
1 ft = 0.3 m
Typically T = 240 - 320 mm

T gl.= (1/50 - 1/70) D - the depth of the rifling is determined by the caliber of the weapon (bullet) and is 1.5 - 2% of its value. For 3-line (7.62 mm) rifles and carbines T gl = 0.12 - 0.15 mm.
To evaluate a weapon, in addition to its caliber, it is necessary to take into account such a characteristic as the length of the cartridge case:
- for heavy machine guns - 100-110 mm;
- for magazine and automatic rifles - 45-55 mm;
- For assault rifles(automatic machines) - 30-40 mm;
- for pistols (submachine guns, revolvers) - 15-30 mm.

Basic specifications(weapon length, barrel length, weight of weapon and ammunition) determine the maneuverability of the weapon.

Correlation between caliber and tactical characteristics of weapons

V beginning = T * L / 0.06 * D², where

T - rifling pitch
D - bullet caliber
L - bullet length

V beginning = K rev. * T, where

To rev. - number of turns of rifling along the length of the barrel

E duln. = m bullets * V² initial.. / 2 = iKV * T / 2, where

i - number of degrees of freedom
KV = 1.38 * 10²³ J/K - Boltzmann constant
T = - 273.15º K = 0ºС

E duln. = E duln. /S, where

S = πD² / 4 - cross-sectional area of ​​the bullet

Combat rate of fire is the number of rounds per minute that can theoretically be fired taking into account the operations of aiming and reloading.
Technical speed is the number of shots per minute that can theoretically be fired without taking into account the operations of aiming and reloading.
Rate of fire - technical speed of an automatic weapon when firing in automatic (continuous) mode.
A shot in which the trajectory does not rise above the aiming line above the target throughout its entire length is called a direct shot.
The range of a bullet is the phase of its movement after the shot until it hits a solid obstacle.

Sighting range is the distance from the muzzle of the barrel to the point of intersection of the aiming line and the flight path.
The effective firing range determines the effectiveness of hitting the target:
- heavy machine guns 2500 m;
- rifles 1500 m;
- pistols 300 m.
The penetrating effect of a bullet is the ability to penetrate various obstacles (penetration depth in obstacles).
The penetrating effect of a bullet depends on the properties of the obstacle, caliber, kinetic energy of the bullet (mass and initial speed) at the moment of meeting the obstacle, as well as on the shape and design of the bullet.
Light bullet of the 1908 model (D bullet = 7.62mm)
Thickness of the penetrated medium (at L = 50 m from the obstacle)
1. Steel plate - 0.6 cm
2. Iron plate - 1.2 cm
3. Gravel - 12 cm
4. Brick wall- 15-20 cm
5. Sand (earth) - 70 cm
6. Wood - 75 -85 cm
7. Soft clay - 80 cm
8. Compacted snow - 350 cm
9. Straw - 400 cm
10. Peat - 2800 cm

The lethal effect of a bullet is the amount of kinetic energy expended by a bullet in the human body.
The destructive ability is the unconditional incapacitation of a person.

E deleted. = 6-8 J/cm² - causes abrasions
14-17 J/cm² - superficial wounds
32-36 J/cm² - non-penetrating wound chest with chest fractures
54-60 J/cm² - penetrating chest injury
135-145 J/cm² - penetrating wound of the chest with damage to its posterior wall

One of the most important characteristics of weapons and ammunition is their caliber. This characteristic largely determines both the power of the cartridge and the quality of the weapon, its dimensions and weight.

Caliber is the diameter of the bore, as well as the diameter of the bullet. Naturally, the calibers of weapons and ammunition must match each other. Everything seems extremely simple. This is not entirely true. In rifled weapons, the diameter of the bore can be measured in two ways - by the distance between opposite fields * or between opposite rifling *. This produces two results. In the territory of the former USSR, as in some other countries, the distance between opposite fields is considered to be a caliber. In a number of other countries - the distance between the grooves. For example, the same designated caliber is 9 mm, for a Makarov pistol it is 9 mm when measured along the margins and 9.2 mm when measured by rifling, and for the Parabellum it is 8.85 mm and 9 mm, respectively.

Weapon caliber-- in rifled weapons - this is the internal diameter of the bore, which is measured between two opposite fields of the rifling (Fig. 1).

*Field-- this is the distance (spacing) between the rifling (protrusions). The caliber of a weapon should not be confused with the diameter of the chamber.

*Rifling --- special recesses (grooves) running along the channel of a rifled weapon along a helical line. The purpose of the rifling is to give the bullet rapid rotation around its longitudinal axis. Depending on the direction of the helix, right-hand rifling and left-hand rifling are distinguished.

With the spread of unitary cartridges, the word “caliber” changed its original meaning and, simultaneously with the concept of “diameter”, also became an indicator of cartridge types. The fact is that the cartridge cases of unitary cartridges are very diverse. Cases of the same caliber can have different lengths and shapes (cylindrical, conical, “bottle”). Therefore, information only about the diameter of the bullet is not enough to get a clear picture of the ammunition. Here an additional characteristic is required that would specify the designation of the ammunition. For example: 9-mm Makarov, 9-mm Browning short, 9-mm Browning long, 9-mm Parabellum cartridges would be indistinguishable if only the numerical characteristics of their caliber were known. Even though they are 9mm, they are completely non-interchangeable.

The calibers of weapons and ammunition are expressed in linear units of measurement --- in millimeters, lines, points or fractions of an inch (the latter are accepted in countries using English system measures), 1 inch is equal to 25.4 mm, 1 line is equal to 2.54 mm, 1 point is equal to 0.254 mm.

The millimeter system is extremely simple and specific, while the inch system contains some conventions that do not always allow translation from one system to another. For example, Caliber 0.30 (thirty hundredths of an inch) corresponds exactly to its designation and is equal to 7.62 mm. The 0.32 caliber is conventional, as 7.65 mm cartridges are designated, but this is not thirty-two hundredths of an inch. Caliber 0.38 is equal to 9.65 mm, and denotes 9 mm cartridges. Therefore, calibers are not transferred from one system to another, but are designated as they were originally designated in the country of origin.

Caliber designation correspondence table,

expressed in millimeters and fractions of an inch

(hundredths in the US, thousandths in the UK).