How is caliber determined? Warfare - caliber
Caliber(from Italian qua libra - “pounds here”) - the diameter of the bore along the rifling or margins; one of the main quantities that determine power firearms .
The caliber is determined by smoothbore weapons according to the internal diameter of the barrel, for a rifled one - according to the distance between the opposite fields of the rifling (in the countries of the former USSR) or according to the distance between the bottom of the opposite rifling (NATO), for shells (bullets) - the largest diameter.. Guns with conical barrel characterized by input and output gauges.
Bullets of various calibers.
The caliber is determined by the internal diameter of the barrel. Barrel 18 calibers long
Caliber of rifled small arms
It is indicated in the USA, Great Britain and a number of other countries in fractions of an inch (in the USA - in hundredths (0.45 inches), in the UK - in thousandths (0.450 inches). When writing, zero and comma are replaced by a dot, and "cal." is used instead of "inch" or omitted altogether ( .45 cal; .450 cal.) In colloquial speech they say: “ forty-fifth caliber", " four hundred and fiftieth caliber".
In other countries it is measured in millimeters - 9×18(the first number is the caliber in millimeters, the second is the length of the sleeve in millimeters). It must be taken into account that the length of the cartridge case is not a characteristic of the caliber, but a characteristic of the cartridge. With the same caliber, cartridges can be of different lengths. A similar “digital” recording is used mainly for military cartridges in the West. For civilian cartridges, the name of the company or a special characteristic of the cartridge is usually added to the caliber, for example forty five Colt,forty-one Smith and Wesson, thirty eight super, three hundred fifty seven Magnum, two hundred twenty Russian (Russian). There are also more complex designations, for example, several designations for the same cartridge: nine millimeter browning short, aka three hundred eighty cars, aka nine by seventeen, aka nine kurtz. This state of affairs is due to the fact that almost every arms company has its own patented cartridges different characteristics, and a foreign cartridge accepted for service or into civilian circulation receives a new designation.
In Russia until 1917 and a number of other countries, caliber was measured in lines. One line = 0.1 inch = 2.54 mm. The name “three-line” has taken root in modern vocabulary, which literally means “a rifle of the 1895 model (Mosin system) of three-line caliber.”
In some countries, the caliber is considered to be the distance between the fields of the rifling (the smallest diameter of the bore), in others - the distance between the rifling (the largest diameter). As a result, with the same caliber designations, the diameters of the bullet and bore are different. An example is the 9x18 Makarov and 9x19 Parabellum.
Makarov has 9 mm - the distance between the fields, bullet diameter - 9.25 mm.
Parabellum has a distance between grooves of 9 mm, respectively bullet diameter 9.02 mm, and the distance between fields is 8.8 mm.
Classification of calibers small arms:
- small-caliber (less than 6.5 mm)
- normal caliber (6.5-9.0 mm)
- large-caliber (9.0-20.0 mm)
Caliber up to 20 mm - weapon. Caliber over 20 mm - artillery.
As a rule, small arms differ from artillery weapons by the type of ammunition. Small arms are designed to fire bullets, and artillery systems fire projectiles. At the same time, for rifled firearms, the main difference between bullets and projectiles as ammunition is the fact that bullets, when passing through the bore, cut into the rifling with their shell. This creates a torque that increases the stability of the bullet in flight. When fired, the projectile is given rotation with the help of driving belts (made from materials of less hardness than the shell of the projectile body). However, this is not the only difference that exists and it is not applicable to all types of artillery and small arms weapon systems.
The most popular calibers of pistols, rifles and machine guns:
577 (14.7 mm) - the largest of the serial ones, the Eley revolver (Great Britain);
.50 (12.7 mm) - used for machine guns and large-caliber sniper rifles. Sometimes for pistols, for example - the Desert Eagle hunting pistol caliber 50 Action Express;
.45 (11.43 mm) - the "national" caliber of the United States, most common in the Wild West. In 1911, the Colt M1911 automatic pistol of this caliber entered service with the army and navy and, repeatedly modernized, served until 1985, when the US armed forces switched to 9 mm for the Beretta 92, and is still used in civilian use.
.40 (10.2 mm) is a relatively new pistol caliber. Provides better efficiency, for which it has gained great popularity in US law enforcement agencies.
.38; .357 (9 mm) - is currently considered optimal for short-barreled weapons (less - the cartridge is “weak”, more - the gun is too bulky and heavy, uncomfortable recoil).
.30 (7.62 mm) - for the Nagan revolver and TT pistol, Mosin rifle, AK assault rifle.
.22 (5.6 mm) - for the TOZ-8 rifle.
.223 (5.56 mm) - y assault rifle M16.
5.45 mm- at the AK-74 assault rifle.
2.7 mm is the smallest serial caliber, used in the Hummingbird pistol of the Franz Pfannl system (Austria).
Methods for measuring the caliber of trunks of various sections Smoothbore weaponsRiflePolygonal slicing
Common mistakes
In television programs and series you can often hear: “9-caliber pistol.” This refers to a 9 mm caliber pistol.
Caliber of Russian artillery, aerial bombs, torpedoes and rockets
In Europe the term artillery caliber appeared in 1546, when Hartmann of Nuremberg developed a device called the Hartmann scale. It was a prismatic tetrahedral ruler. On one side were marked the units of measurement (inches), on the other three the actual dimensions, depending on the weight, in pounds, of the iron, lead and stone cores respectively.
Example(approximately):
1 face - mark lead kernels weighing 1 lb - corresponds to 1.5 inches
2nd face - iron cores 1 lb. - from 2.5
3rd side - stone cores 1 lb. - from 3
Thus, knowing either the size or weight of the projectile, it was possible to easily assemble, and most importantly, manufacture ammunition. A similar system existed in the world for about 300 years.
In Russia, before Peter I, there were no uniform standards. The cannons and squeaks available in the army were each characterized separately by the weight of the projectile, in Russian national units. Pre-Petrine Inventories mention guns ranging from 1/8 hryvnia to a pood. At the beginning of the 18th century, on behalf of Peter I general-feldtzeichmeister Count Bruce developed a domestic caliber system based on the Hartmann scale. She divided the tools according to artillery weight projectile (cast iron core). The unit of measurement was artillery pound- a cast iron ball with a diameter of 2 inches and a weight of 115 spools (about 490 grams). It did not matter what types of projectiles the gun fired - buckshot, bombs or anything else. Only the theoretical artillery weight that a gun could fire given its size was taken into account. Tables were also developed correlating artillery weight (caliber) with bore diameter. Artillery officers were required to operate with both calibers and diameters. In the “Book of Naval Regulations” (St. Petersburg, 1720), in Chapter Seven “About the artillery officer, or constapel”, in paragraph 2 it is written: “You must measure the cannonballs to see if their diameters are similar to the calibers of the guns and place them on the ship according to to their places." This system was introduced by royal decree in 1707 and lasted for more than a century and a half.
Example:
3-pounder gun, 3-pounder gun- official name;
artillery weight 3 pounds- the main characteristics of the weapon.
size 2.8 inches- bore diameter, an auxiliary characteristic of the gun.
In practice, it was a small cannon that fired cannonballs weighing about 1.5 kg and had a caliber (in our understanding) of about 70 mm.
D. E. Kozlovsky in his book gives a translation of Russian artillery weight into metric calibers:
3 lbs - 76 mm
Explosive shells (bomb) occupied a special place in this system. Their weight was measured in pounds (1 pood = 40 trade pounds = approx. 16.3 kg). This is due to the fact that the bombs were hollow, with explosives inside, that is, made of materials of different densities. During their production, it was much more convenient to operate with generally accepted weight units.
D. Kozlovsky gives the following relationships:
1/4 pood - 120 mm
A special weapon was intended for bombs - a bombard, or mortar. Her performance characteristics, combat missions and calibration system allow us to talk about a special type of artillery. In practice, small bombards often fired ordinary cannonballs, and then the same weapon had different calibers - general at 12 pounds and special at 10 pounds.
The introduction of calibers, among other things, became a good financial incentive for soldiers and officers. Thus, in the “Book of Marine Charter”, printed in St. Petersburg in 1720, in the chapter “On rewarding” the amounts of reward payments for guns taken from the enemy are given:
30 pound - 300 rubles
2 and below - 15
In the second half of the 19th century, with the introduction of rifled artillery, the scale was adjusted due to changes in the characteristics of the projectile, but the principle remained the same.
Interesting fact: Nowadays artillery pieces, calibrated by weight, are still in service. This is due to the fact that in Great Britain a similar system was maintained until the end of the Second World War. Upon completion a large number of guns were sold and transferred to the countries of the so-called Third World. In Great Britain itself, 25-pounder (87.6 mm) guns were in service until the end of the 70s of the last century, and now remain in fireworks units.
In 1877, the inch system was introduced. At the same time, the previous sizes on the “bruce” scale to new system had nothing to do with it. True, the “Bryusov” scale and artillery weight remained for some time after 1877 due to the fact that many obsolete guns remained in the army.
Example:
“Six-inch gun” of the cruiser “Aurora”, with a shot from which it allegedly began October Revolution , had a caliber of 6 inches or 152 mm.
From 1917 to the present, caliber has been measured in millimeters. In the USSR and Russia it is measured by the rifling fields (the smallest bore diameter). In the USA, Great Britain and some other countries according to their bottoms (largest diameter), but also in millimeters.
Sometimes the caliber of a gun is used to measure the length of the barrel.
Examples:
153 mm howitzer, 20 calibers (or 153/20). Finding out the barrel length is quite simple.
24-pounder gun, 10 calibers. Here you first need to find out in which system the gun is calibrated.
The caliber of aircraft bombs, measured in kilograms or pounds (for non-nuclear bombs) or power expressed in kilotons/megatons TNT equivalent(for nuclear bombs). It should be noted that the caliber of a non-nuclear bomb is not its actual weight, but its correspondence to the dimensions of a certain standard ammunition (which is usually a high-explosive bomb of the same caliber). The discrepancy between caliber and weight can be quite large - for example, the SAB-50-15 illumination bomb had a 50-kg caliber and weighed no more than 15 kg (a discrepancy of 3.5 times). On the other hand, the FAB-1500-2600TS aerial bomb has a caliber of 1500 kg and a weight of 2600 kg (the discrepancy is more than 1.7 times).
The caliber of torpedoes is measured in mm by their diameter.
Caliber rockets(unguided rockets) are measured in mm by their diameter. In this case, the length indicated in the calibers serves as an important characteristic. Feathered projectiles are 20 calibers long, and turbojet projectiles are 6-8 calibers long.
Notes
- It must be taken into account that the projectiles have sealing belts made of soft metal, which prevent the breakthrough of gases between the projectile and the walls of the barrel bore. According to the obturating belts, the largest diameter of the projectile will be greater than its caliber. For example, copper sealing bands of 125-mm tank smoothbore gun shells ensure firing with barrel wear of up to 3.3 mm (that is, the actual caliber of a 125-mm gun with wear can be 128 mm).
- IN THE USSR ( Russian Federation) the term “small-caliber” is usually used to refer to rimfire cartridges. For cartridges with a center fire, the term “low-impulse” is also adopted.
- There are also exceptions:
- the aforementioned 4th hunting gauge used in signal pistols
- there are rifles for 20mm artillery shells
- carbine KS-23
- underbarrel grenade launchers and other systems for the same grenades are also classified as small arms table
1. The distance between two opposite grooves.
2. Inner diameter of the bore.
3. Distance between fields and grooves.
4. The distance between two opposing fields.
4. Purpose of the mainspring valve:
1. Serves for fastening the mainspring and handle with screw.
2. Serves to attach the mainspring, handle with screw and hold the magazine at the base of the handle.
3. Serves to attach the mainspring to the base of the handle.
5. Purpose of the handle base:
1. Serves for store premises.
2. Serves to attach the handle.
3. Serves for fastening the mainspring.
4. Serves for all of the above.
6. Purpose of the shutter delay reflector:
1. Serves to hold the cartridge case in the bolt cup.
2. Serves to increase the flight range of the cartridge case.
3. Serves to prevent reflection of the shutter surface when aiming.
4. To increase the lethal effect of the bullet.
5. Serves to eject the cartridge case out through the bolt window.
7. Purpose of the pistol frame:
1. For attaching the barrel and trigger guard.
2. For attaching the base of the handle, barrel, trigger guard and making it easier to hold the pistol in your hand.
3. The frame serves to connect all parts of the gun.
8. Purpose of the pistol barrel:
1. Serves to direct the flight of the bullet.
2. Serves to put a return spring on it.
3. Serves to place a cartridge in it.
4. Serves to impart rotational motion to the bullet.
9. Purpose of the trigger rod with the cocking lever:
1. For decocking the hammer and cocking the hammer when pressing the tail of the trigger.
2. For self-cocking shooting.
3. For all of the above.
10. Purpose of the return spring:
1. Serves to activate the hammer, cocking lever and trigger rod.
2. Serves to lock the barrel bore when firing.
3. Serves to return the bolt to the front position after firing.
11. Purpose of the mainspring:
1. To activate the trigger.
2. To operate the cocking lever.
3. To activate the trigger rod.
4. For all of the above.
12. Purpose of wiping the gun:
1. To disassemble the pistol.
2. To reassemble the pistol after disassembling.
3. To clean the gun.
4. To lubricate the gun.
5. For all of the above.
13. Shutter purpose:
1. To cock the trigger.
2. To remove the cartridge.
3. To lock the bore when firing.
4. To hold the sleeve.
5. To feed a cartridge from the magazine into the chamber.
6. For all of the above.
14. Purpose of a pistol holster:
1. For carrying and storing a pistol, spare magazine and cleaning.
2. For the convenience of carrying a pistol.
3. To practice exercises during practical shooting.
15. Purpose of the notch between the front sight and the rear sight:
1. To prevent reflection of the shutter surface when aiming.
2. For the convenience of retracting the shutter by hand.
16. Purpose of the trigger:
1. To strike the striker.
2. To strike the striker.
3. To strike the bolt.
17. Purpose of the trigger:
2. For decocking and cocking the hammer when firing by self-cocking.
3. For cocking the hammer when firing by self-cocking.
4. To press it with your index finger.
5. To connect to the front trigger rod pin.
18. Purpose of the drummer:
1. To perceive the trigger blow.
2. To break the cartridge primer.
3. To strike the striker.
19. Purpose of the pistol slide stop:
1. To hold the pistol bolt in the rearmost position.
2. To hold the bolt in the forward position after firing.
3. To hold the bolt in the rear position after all the cartridges from the magazine have been used up.
20. What are the bore fields of rifled firearms called?
1. The distance between two opposite grooves.
2. Width of rifling.
3. The distance between opposite fields.
4. Gaps between cuts.
21. Purpose of the pistol strap:
1. To ensure the pistol is attached to the waist (trouser) belt.
2. For ease of carrying the PM in a holster.
3. To prevent loss of the PM and its falling out of the holster.
22. Purpose of the notches on the sides of the shutter:
1. To prevent reflection of the shutter surface when aiming.
2. For the convenience of retracting the shutter by hand.
3. For all of the above.
23. Purpose of the wide mainspring feather:
1. To actuate the cocking lever with the trigger rod.
2. To activate the trigger.
3. To operate the trigger.
24. Purpose of the fuse:
1. To press it with your finger.
2. To perceive the trigger blow.
3. To hold the firing pin in the bolt.
4. To ensure safety when handling the gun.
25. Purpose of the trigger guard:
1. To hold the shutter in the rearmost position.
2. For attaching the trigger.
3. To protect the trigger from accidental pressing.
4. To limit the movement of the shutter to the rear extreme position.
26. Purpose of the handle with a screw:
1. For attaching the mainspring to the base of the handle.
2. To cover the base of the handle and make it easier to hold the pistol in your hand.
3. To hold the gun.
27. Purpose of the store:
1. To hold eight rounds.
2. For insertion into the base of the handle.
3. To ensure the supply of cartridges from the magazine to the chamber.
4. For all of the above.
28. Purpose of the feeder tooth:
1. To turn on the bolt delay when all the cartridges from the magazine are used up.
2. To hold the bolt in the rear position after all the cartridges from the magazine have been used up.
3. To hold the feeder in the magazine body.
29. Purpose of a sear with a spring:
1. To release the trigger from cocking.
2. To keep the trigger cocked.
3. To hold the trigger on the combat and safety cocks.
4. To keep the trigger on the safety cock.
5. For gripping the trigger ledges.
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.
| In mm. | USA | Great Britain | The true value of the barrel caliber in mm. |
|---|---|---|---|
| 5,6 | .22 | .220 | 5,42-5,6 |
| 6,35 | .25 | .250 | 6,1-6,38 |
| 7,62-7,63 | .30 | .300 | 7,6-7,85 |
| 9,0 | .35 | .350 | 8,70-9,25 |
| 9,0-9,3 | .38 | .380 | 9,2-9,5 |
| 10,0 | .40, .41 | .410 | 10,0-10,2 |
| 11,43 | .45 | .450 | 11,26-11,35 |
| 12,7 | .50 | .500 | 12,7 |
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.
There are the following calibers of hunting rifles measured by the number of round caliber (150 mm from the breech) bullets made from one English pound (453.6 g) of pure lead: 2, 4, 8, 10, 12, 16, 20, 24, 28, 32 .
Calibers of hunting rifles produced today in Russia (and the USA): 12, 16, 20, 24, 28, 410; (10, 12, 16, 20, 24, 28, 410).
Diameters of the most popular barrel bores hunting calibers different countries:
| Manufacturer country | 4 | 8 | 10 | 12 | 16 | 20 | 24 | 28 | 32 | 410 |
|---|---|---|---|---|---|---|---|---|---|---|
| Russia | - | - | 20,00–20,25 | 18,20–18,75 | 17,00–17,25 | 15,50–15,75 | - | 14,00–14,25 | 12,50–12,75 | 10,20–10,60 |
| Germany | 23,40–23,80 | 20,80–21,20 | 19,30–19,70 | 18,20–18,60 | 16,80–17,20 | 15,70–16,10 | 14,70–15,10 | 13,80–14,20 | 12,70–13,20 | 10,20–10,60 |
| England | min 23.75 | min 21.21 | min 19.68 | 18,52–18,92 | 16,82–17,22 | 15,62–16,13 | min 14.71 | min 13.96 | min 13.36 | - |
| Belgium | - | - | - | 18,40–18,60 | 16,80–17,00 | 15,60–15,80 | - | - | - | - |
| Italy | - | - | - | 18,40–18,60 | 16,80–17,00 | 15,60–15,80 | - | - | - | - |
| USA | 23,6 | 21,21 | 19,69–20,20 | 18,42–18,93 | 16,89–17,40 | 15,62–16,13 | 14,73–14,85 | 13,80–13,95 | 12,70–12,85 | 10,41–10,92 |
| France | - | - | 19,30–19,70 | 18,20–18,50 | 16,80–17,20 | 15,60–16,00 | 14,70–15,10 | 13,40–14,00 | - | - |
| Czech | - | - | - | 18,20–18,35 | 16,80–16,95 | 15,70–15,85 | 14,70–14,85 | 13,80–13,95 | 12,70–12,85 | 10,20–10,35 |
| PMK | - | - | 19,69–20,20 | 18,20–18,60 | 16,80–17,20 | 15,70–16,10 | 14,70–15,10 | 13,80–14,20 | 12,70–13,10 | 10,20–10,60 |
PMK - Permanent International Commission of the Brussels Convention for the Testing of Hand Firearms.
| The ratio of numbers, diameters and mass of shot and buckshot of domestic production: | The ratio of numbers and diameters of shot and buckshot made in the USA: | ||||
|---|---|---|---|---|---|
| Fraction number | D, mm | Weight, g | Fraction number | D, inch | D, mm |
| 11 | 1.50 | 0.015 | 9 | .08 | 2.0 |
| 10 | 1.75 | 0.03 | 8.5 | .085 | 2.2 |
| 9 | 2.0 | 0.05 | 8 | .09 | 2.3 |
| 8 | 2.2 | 0.07 | 7.5 | .095 | 2.4 |
| 7.5 | 2.40 | 0.08 | 6 | .11 | 2.8 |
| 7 | 2.50 | 0.09 | 5 | .12 | 3.0 |
| 6 | 2.75 | 0.12 | 4 | .13 | 3.3 |
| 5 | 3.0 | 0.15 | 3 | .14 | 3.6 |
| 4 | 3.25 | 0.20 | 2 | .15 | 3.8 |
| 3 | 3.50 | 0.25 | 1 | .16 | 4.0 |
| 2 | 3.75 | 0.30 | bb | .18 | 4.6 |
| 1 | 4.0 | 0.37 | bbb | .19 | 4.8 |
| 0 | 4.25 | 0.50 | t | .20 | 5.0 |
| 00 | 4.5 | 0.55 | tt | .21 | 5.8 |
| 000 | 4.75 | 0.65 | |||
| 0000 | 5.0 | 0.75 | |||
| Buckshot: | |||||
| 5.25 | 0.85 | 4 | .24 | 6.1 | |
| 5.6 | 1.0 | 3 | .25 | 6.4 | |
| 5.7 | 1.1 | 2 | .27 | 6.9 | |
| 5.8 | 1.15 | 1 | .30 | 7.6 | |
| 5.9 | 1.2 | 0 | .32 | 8.1 | |
| 6.2 | 1.4 | 00 | .33 | 8.4 | |
| 6.5 | 1.6 | 000 | .36 | 9.1 | |
| 6.8 | 1.85 | ||||
| 6.95 | 2.0 | ||||
| 7.15 | 2.15 | ||||
| 7.55 | 2.5 | ||||
| 7.7 | 2.7 | ||||
| 8.0 | 3.0 | ||||
| 8.5 | 3.6 | ||||
| 8.8 | 4.0 | ||||
| 9.65 | 5.3 | ||||
| 10.0 | 5.9 | ||||
Sources:
Caliber is the diameter of the bore, expressed in different measures. The calibers of smoothbore guns from 4 to 32 are still, following tradition, designated by the number of round caliber (equal to the caliber of the barrel) bullets cast from one English trade pound of lead, equal to 453.6 g. It is trade for in the Anglo-Saxon system There is also another pound - pharmaceutical pound (373.2 g). If a pound of lead produces 12 caliber ball bullets, then the gun will be 12 gauge, if it is 20-20 gauge, etc. The larger the number indicating the caliber, the smaller the bore diameter (caliber).
Since the walls of a metal sleeve are thinner than those of a paper (plastic) sleeve, the bores of barrels made for a metal sleeve have a larger diameter than the bores of barrels made for a paper (plastic) sleeve. Nowadays, almost all guns are produced with a paper (plastic) cartridge case.
The caliber of large-caliber fittings for black powder was designated in the same way as smooth-bore guns: there were fittings of 12, 16, 29 and other calibers. Calibers rifled weapons were also indicated in lines, and are now indicated either in mm (5.6; 7.62; 11.43), or in fractions of an inch.
First of all, you should remember the following data: 1 inch = 10 lines = 100 dots; 1 inch = 25.4 mm; 1 line = 2.54 mm; 1 point = 0.254 mm; 1/10th of a point = 0.0254 mm. Based on this, we can easily understand any caliber designation system and translate caliber designations from one system to another. For example, S.I. Mosin’s three-line rifle has a caliber of 3×2.54 = 7.62 mm. Since in the USA calibers are expressed in hundredths of an inch (in other words, in points), then caliber 30 must be multiplied by 0.254, and the English caliber 300 by 0.0254, because in the UK calibers are indicated not in hundredths, but in thousandths of an inch ( i.e. in tenths of a point). In this case, we get: 30 × 0.254 = 7.62 mm; 300×0.0254 = 7.62 mm.
As you can see, caliber 3 lines, caliber 30, caliber 300 caliber 7.62 mm are equal to each other, but expressed differently. In the same way, it is easy to verify that calibers 2.2; 22; 220 is equal to 5.6 mm, i.e. the caliber of small-caliber weapons widespread throughout the world.
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, which sometimes leads to confusion. Thus, the caliber of a 5.6 mm rifle is sometimes designated as 5.45 mm. In the first case, the caliber is measured by rifling, in the second - by margin.
We produce smoothbore weapons in five calibers - 12, 16, 20, 28 and 32. According to the standards, 10-gauge is also provided, but such guns are not produced. We have no longer made 8-caliber guns for a long time, and at the end of the 1940s, the 24-caliber was excluded from the standards and soon the production of guns of this caliber ceased. IN international system shotgun calibers, this caliber remains.
In Russia they make guns with barrels following sizes: 12 gauge - 18.2–18.7 mm; 16th - 17–17.25 mm; 20th - 15.7–15.95 mm; 28th - 14–14.25 mm; 32nd - 12.5–12.75 mm.
Gun barrels of calibers from 12 to 28 inclusive are made for a paper sleeve, and 32 for a metal sleeve.
The Tula Arms Plant produces 12-gauge weapons with bore diameters of 18.5–18.7 mm, and the Mechanical Plant in Izhevsk produces 18.2–18.25 mm. We advise you to remember this circumstance: when equipping cartridges at home, this is very important to take into account.
Sources:
It is customary to denote the caliber of large-caliber shotguns and rifles by the number of round bullets from a pound of pure lead: 12 gauge - that means 12 bullets can be made from 0.410 kg (1 pound) of lead for such a barrel, 24 means 24 bullets, etc.; This means that the larger the number, the smaller the diameter.
But the pounds are different countries different, and did not always drill accurately, then they began to make cartridges from different materials, with different wall thicknesses, and the barrels were drilled along the internal channel of the sleeve. It is clear that with the same outer dimensions of the liner, its internal channel is wide if the walls are made of thin sheet brass, and much narrower if the walls are made of thick folder. The name in both cases remains the same according to custom, although this does not at all correspond to the real diameter of the trunk and still misleads many insufficiently knowledgeable hunters.
Even in barrels for the same 12-cal folder cartridges. There are huge differences, reaching up to ¾ mm, and are greatly reflected in the selection of supplies, especially wads. And it is clear that a bullet too loose for an 18.8 mm barrel will be able to inflate or rupture an 18.2 mm barrel.
But these are all measurements of barrels for a 12 caliber paper sleeve. Barrels for thick brass are drilled at 19.35–19.20 mm, and for thin brass at 19.60 mm; it is clear that in reality this is a different caliber, suitable for 10 cal. under the folder sleeve, here the charge and wads should be different.
It is very easy to find out for which sleeve the barrel is drilled by the stamps, since the stamps are placed according to the actual caliber and by measuring it: a wad is driven from the treasury approximately a quarter (17–18 cm) into a clean, slightly lubricated barrel and “wax” is poured , paraffin, etc., and best of all sulfur cuttings; When the casting hardens, it is pushed out of the barrel. If the barrel (as in the vast majority of cases happens) is made for a folder sleeve, then the muzzle end of the casting will fit into the folder sleeve with a slight gap, and into the brass case with a very large gap. If the barrel is made for a brass sleeve, then the end of the casting will not fit into a folder.
Sources:
- — Moscow: Publication of the All-Khotsoyuz. - 1929.
Total articles
A hunter is not just a man with a gun; first of all, he is a man with a big soul.
If you look at the trunk superficially, it may seem that it is just a pipe, almost like a water pipe. And, like all pipes, weapon barrels differ in diameter, which in relation to weapons is usually called caliber.
What are the calibers of hunting rifles?
The answer is simple - the diameter of the bore. Correct, but to a first approximation. The fact is that the barrel bore has a complex profile. But we’ll come back to this a little later.
When talking about shotguns, we usually say: “12-gauge, 16-gauge, 20-gauge, 28-gauge, or 32-gauge shotgun.” At the same time, we know for sure that a 28-caliber shotgun has a thinner bore than a 12-gauge shotgun. It is clear that these numbers are not units of length.
The caliber rating (4-gauge, 8-gauge, 10-gauge, 12-gauge, etc.) corresponds to the number of round bullets cast from an English pound of lead.
It’s no easier with nomenclature rifled weapons. The famous Russian Mosin rifle is called a three-line rifle, and the caliber of the Simonov self-loading carbine is indicated in millimeters - 7.62, with completely identical barrel bore diameters.
Shotgun calibers
Let's try to figure it out first with smooth-bore weapons. Now in Russia they produce guns of only five named calibers.
But earlier, in addition to them, guns of 4, 8, 10 and 24 calibers were produced. The numbers denoting these calibers correspond to the whole number of round bullets produced from one English (trade) pound of lead (453.6 g).
This definition allows for a simple but useful equation: K x M = 453.6 g, where K is the caliber of the barrel, M is the mass of a round bullet with a diameter equal to the diameter of the barrel bore.
This equation makes it possible to calculate three important parameters:
- The mass of a round bullet of any caliber is obtained by dividing 453.6 g by caliber;
- If we substitute the mass of the bullet, expressed in terms of the volume of the ball and the density of lead (11.34 g/cm3), it is easy to calculate the barrel diameter (in mm) for any caliber. It is equal to 42.5/(cube root of caliber). The caliber can be determined if the bore diameter is known;
- The caliber is equal to the third power of the ratio 42.5 / (barrel bore diameter in mm).
History of calibers
At the beginning of the last century, all integer calibers (4, 5, 6, 7, and so on up to 36) were in use. It seems very strange that such an irrational designation of calibers has survived to this day.
After all, designations of calibers in linear units, especially decimal ones, would be incomparably simpler and clearer. However, our general inertia is very great.
At the beginning of the 19th century, Napoleon Bonaparte tried to introduce a definition of calibers in terms of the number of bullets along the diameter of the barrel, which is obtained not from a pound, but from a kilogram of lead. French guns of that period occasionally show traces of that reform. A 12-gauge shotgun was designated 40 in Napoleonic style.
Shotgun bore profile
From the breech there is a chamber - a socket for a cartridge. The chamber begins with a groove under the rim of the sleeve. Its total depth for a 12-gauge shotgun is 1.9 mm. The first half is a cylinder with a diameter of 22.5 mm, the second is a cone with an apex angle of about 80 degrees.
This groove under the rim of the cartridge case not only positions the bottom of the cartridge case in the plane of the breech cut of the barrels, but also, with the help of a cone, centers it in the chamber. The chamber is a truncated cone, expanding towards the breech by 0.3 mm. This is necessary for free removal of the spent cartridge case.
The length of the chamber must match the length of the cartridge case. Longer cartridges lead to unacceptably high pressures of powder gases in the barrel when fired; cartridges that are shorter than the chamber lead to uneven pellet and sharpness and, in addition, ruin the chambers.
Shells for shotguns
Our industry produces guns for cartridges with lengths of 70 and 76.2 mm. These dimensions are based on the inch system. In the world, chambers are made from 51 to 89 mm long. A generally accepted standard requires that the length of the cartridge case in the unwound state be marked on the finished cartridge.
In addition, when indicating the caliber of a smooth-bore weapon, the length of the cartridge case is written through a slash. For example. 12/70 or 20/76. Some hunters have a misconception that in order to easily remove metal cartridges from the chamber, they must almost dangle in it. In fact, the brass sleeve in the chamber must fit tightly so that when fired, its deformation does not exceed the elastic limit. If a loose chamber allows the case to reach the limits of plastic, irreversible deformation, it will be very difficult to remove it.
In order for a gun to be able to fire using cartridges of different designs (with different wall thicknesses), a transition cone or projectile entrance follows the chamber. Cases made from different materials have different internal diameters of the barrels, which differ from the diameter of the barrel bore. The purpose of the transition cone is to prevent the breakthrough of powder gases either into the shot charge or into the gap between the chamber and the sleeve when the projectile passes from the chamber to the barrel.
To prevent such a breakthrough, it is necessary that the height of the felt wad be at least one and a half times greater than the length of the transition cone. Its profile varies, but the length rarely exceeds 10 mm. Behind the transition cone the actual barrel channel begins, which continues to the muzzle device. In rare cases when it is not present, the channel continues to the muzzle without a significant change in diameter.
Thus, the caliber in a smoothbore gun is the internal diameter of the barrel from the projectile entrance to the muzzle device.
Practical difficulties
Now in theory everything seems certain, but in practice there are a couple of complications. Each company has its own tool sizes and equipment for processing barrel bores of each caliber. Even in our country of complete standardization, the Tula Arms Plant produces 12-gauge shotguns with a bore diameter of 18.5-18.7 mm, and the mechanical plant in Izhevsk produces 18.2-18.45 mm.
Moreover, practically the barrel channels are not a strict cylinder, but a truncated cone. From the chamber to the muzzle they taper slightly. This expansion in the breech occurs naturally. Any deep hole on the entry side of the processing tools becomes slightly wider. However, this imperfection also plays a positive role.
Moving from the chamber, the wad, while somewhat abraded, still does not stop working (preventing breakthrough of powder gases) because the diameter of the channel decreases. This reasoning fully applies to both the traditional felt wad and the polyethylene seal wad.
For the sake of fairness, it should be noted that the best piece gunsmiths make special efforts, and their barrels between the transition cone and the muzzle device really have a constant diameter, they are a real cylinder.
In addition, sometimes a small cone is specially made in the first third of the channel (from the breech).
Returning to the definition of the caliber of a shot barrel, we must understand some conventions of this parameter.
Typically, shotguns have choke tubes, the main purpose of which is to finally form the shotgun. Barrels without choke constrictions are rare in smoothbore shotguns, although they tend to shoot better with zeros. Such trunks are called “cylinders”.
What is a choke and what is it for?
The most common form of constriction is called a “choke.”
From the muzzle side, it is a cylinder, the longer the greater the narrowing.
- A full 12 gauge choke is 18mm long. It mates with the main channel with a sloping conical surface (taper 1:120);
- The payday has a cylindrical part length of 10 mm.
Let's first define the concept of "chok".
This narrowing of the shotgun bore is located near the muzzle. This narrowing is very rarely made by more than 40 thousandths of an inch (in the metric system - 1.01 mm). Each "thousandth" can be considered as a unit of reduction.
More details about the marking of checks can be found in the article: “Marking of replaceable chokes”.
The barrels of guns intended for shooting on a round platform have wider chokes: from 10 thousandths to a strict cylinder. High-end shotguns for this exercise are sometimes made with a choke drill, but on the muzzle side a “bell” of 10-15 thousandths of an inch is made.
Currently, many manufacturers of hunting and sporting weapons equip their weapons with replaceable chokes, which are light tubes that are screwed into the barrel from the muzzle side. A special key is included for this purpose.
Choke shapes
Replaceable chokes are sometimes made in the form of barrel extensions, usually not exceeding 150 mm.
However, the famous French company Verneuil Carron made a real revolution by producing a series of barrel extensions for semi-automatic shotguns with a length of 820 mm.
Designation of chokes size
There are different options for indicating the size of the chokes (not yet general standard). One of them is to use asterisks: * - full choke, ** - 3/4 choke, *** - half choke, **** - quarter choke or cylinder.
Other manufacturers use the letter “0” to designate chokes. For example, the Beretta company puts the “0000” sign on the cylinder. This means that the barrel is truly cylindrical. And on the free ends of the replaceable chokes you can see small marks. And again, one risk corresponds to a full choke.
Choke profiles vary not only for ballistic reasons, but also based on the type of shot. Nowadays, the problem of replacing lead shot with steel shot is very urgent to improve the environmental situation in reservoirs where waterfowl are intensively hunted.
However, the use of steel shot requires very smooth transitions in the bores. Otherwise, they will experience catastrophic wear. To prevent this from happening, modern manufacturers of shotguns make all transitions in bore diameters hyperbolic.
In addition to the “regular” choke, barrels with several other options for muzzle devices are produced around the world.
The complexity and variety of profiles of smooth-bore weapons, even of the same caliber, must be taken into account when selecting wads, gaskets and, of course, bullets not only for each gun, but also for each barrel. It is almost certain that the left and right barrel (top and bottom) of a shotgun will "prefer" different designs of zeros.
Types of channel drilling
Speaking about gun calibers, we must talk about two types of channel drilling, which allow you to shoot both shot and bullets at incomparably greater distances than from conventional smoothbore guns. We are talking about a rifled choke - a paradox and Lancaster drilling, in which the barrel bore has an oval cross-section, “twisted” with a pitch of a regular rifling.
Fortunately for our hunters, weapons with such barrels are formally considered smoothbore. This allows you to purchase it under the same licenses as regular hunting smoothbore weapons.
Shapes of muzzle devices
Muzzle device shapes (top to bottom):
- a) normal conical choke;
- b) choke with pre-muzzle expansion;
- c) bell with pre-barrel constriction;
- d) parabolic choke;
- e) normal bell;
- e) strong choke;
- g) rifled choke (paradox).
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