Large caliber weapon. Calibers of smoothbore hunting rifles, expressed in millimeters. We distinguish not only the caliber, but also the length of the sleeve

The caliber is an integral part of the hunting small arms and, despite the fact that we meet with this concept all the time, get used to it, do not always think about what it is.

Let's try to define the word caliber. Often there are definitions where the diameter of the bore is considered to be the caliber, but this is not entirely true, because. caliber is not only the diameter of the bullet, but also the length of the case, its shape, and much more. For example, the caliber of smoothbore guns does not tell us anything at all about the diameter of the bore, because. the number of caliber means the number of caliber bullets of spherical shape, ideally passing through the bore and having the same size, cast from one English pound of lead (453.59 g). Why English? Because, for example, in Russia a pound is equal to 409.5 g, in order to come to a single measure of measurement, the English pound was taken as the standard.

Rifle calibers

In this section, first of all, I would like to explain what a rifled weapon is.

A rifled weapon is a type of weapon that uses special rifling in the bore that gives the bullet a rotational motion, due to which it is better stabilized in flight and maintains high accuracy over a long distance of the path.

There are 3 main systems of measures for designating calibers:

1) American - measured in hundredths of an inch (0.01) * - e.g. 45 ACP **

2) Imperial - measured in thousandths of an inch (0.001)* - e.g. 416 Rigby **

3) Metric - measured in millimeters with the addition of the sleeve length, through the multiplication sign. - for example 7.62x39

To complete the picture, it should be noted that until about 1917, a number of countries used a measure of calibers in lines, where one line is 0.1 inches. *

It is thanks to this measure of calibers that we remember the legendary “Three-ruler”, which was simply a designation for a caliber equal to 0.3 inches, i.e. 7.62 mm, and the rifle itself was called "Mosin Rifle caliber 7.62x54".

In rifled calibers, it is very important to preserve the full designation, otherwise it is almost impossible to understand what caliber is in front of us. This is equally characteristic of both the metric system and others. It is not enough to just know the diameter of the bullet, for example, 7.62 can be 7.62x39, and 7.62x54, and 7.62x66 or take .416, it can be Rigby, Remington Magnum, Barret, etc. - all these are completely different calibers, with different initial speed, kinetic energy and ballistic coefficient and scope.

* An inch equals 2.54 cm.

** However, it is worth noting that this rule has exceptions, so these measurements are rather traditional.

Shotgun calibers

A smoothbore weapon can be described as a weapon with smooth bore walls that allows it to fire a wide range of ammunition that fits in diameter.

As it was written above, the caliber of a smoothbore weapon is measured by the number of caliber bullets cast from an English pound of lead, i.e. the larger the barrel diameter, the fewer caliber bullets can be cast and the larger the caliber obtained. As a result, 16 gauge is less than 12, but more than 20.

However, manufacturers of smoothbore guns still focus on the diameter of the bore in the production of guns and rarely deviate from the following dimensions:

For 12 gauge 18.20-18.90mm,

For 16 gauge 16.80-17.30 mm,

For the 20th caliber 15.70-16.20 mm.

Most often, each individual manufacturer is characterized by narrower barrel diameters than indicated. For example, Italian and domestic gunsmiths use 12 gauge barrel drilling within 18.4 - 18.6 mm, English 18.5-18.7 mm, Belgian 18.4-18.9 mm. Some firms are introducing new drills, where the diameter of the bore narrows from the chamber to the muzzle, which should increase the sharpness of the battle.

The most common calibers in the Russian Federation are 12.16 and 20 calibers, 28 and even more so 32 calibers are rarely used.

There are exceptions to every rule, and so it is in the measurement of smoothbore calibers. Caliber 410, although rarely used for hunting, is quite common in training weapons, because. It has low recoil and cheap ammo. It can be seen from the designation that the caliber is indicated in thousandths of an inch (which, however, does not cancel its American origin), this is due to the origin of the caliber at the beginning of the last century (or even earlier) when, for the sake of economy, it was easier to use one gun for both bullet and shot hunting.

Gun calibers

Barrel artillery calibers most often use the measurement format in the metric system. Based on the projectile diameter and case length, for example 20x110 Hispano Suiza, sometimes shortened to 20 mm Hispano. The exception, most often, are very large caliber ship-based or coastal/railway-based guns. In these cases, the caliber is measured in inches.

Copyright 2013 Sergey Sokolov. When using the article, be sure to refer to 

No, we are not talking about ammunition capable of breaking through the teapot. I will try to convey the basic basics of the differences, markings and designations of small arms calibers as simply and accessible as possible. And also, I can answer your questions in the comments.

So, the caliber - it would seem nothing complicated. We have all heard these hackneyed phrases hundreds or thousands of times - "caliber nine millimeters", "caliber seven sixty-two millimeters", "three-ruler", 12 gauge, 45 gauge, etc.

But why is the 12th caliber larger than the 9th, and the 45th is smaller than the 12th, but larger than the 9th, and 7.62 simultaneously fits the Nagant revolver, TT pistol, Kalashnikov assault rifle and "three-ruler" ???

Technically, the concept of caliber implies the diameter of the barrel between opposite grooves (in rifled) and walls (fields) in smoothbore weapons.

In order to understand at least a little where all these calibers, grains, ages and lines came from, it is worth looking back a little at the history and geography of systems for measuring dimensions and mass. So, today we use the metric system, and we measure weight in grams.

America, Britain and some other countries use non-metric systems of measurement. As a result, confusion arises. And also the units of measurement of those years when certain standards of calibers and ammunition were actually created in weapons terminology.

First consider key points metric system. So, the caliber in the metric system will look like this - rounded bullet caliber (barrel rifling diameter) X approximate length of the sleeve from the base to the rims. That is, 9x19 mm, 7.62x25 mm, 7.62x39 mm, 7.62x54 mm, 9x39 mm, etc.

Actually, understanding this is already enough to answer some of the questions related to caliber. But if you go a little deeper, additional questions arise. The fact is that the length of the sleeve and the diameter of the bullet are not all factors of caliber. There are a huge number of other nuances - the type of ignition of the cartridge, the type of primer, the shape of the cartridge case and the type of extraction, the shape of the bullet itself, the "stuffing" of the bullet, its weight and other equally interesting details.

I will not touch on everything, since most people are simply not interested in them, and then the material will be of a completely different scale.

Let's move on to our foreign colleagues. In the USA, the caliber is indicated in inches:

Inch (from the Dutch. duim - thumb) - a unit of distance in some European non-metric systems of measures. Historically - width thumb adult male. Usually an inch is equal to 1/12 or 1/10 (“decimal inch”) of a foot of the corresponding country (in Russian and English systems of measures, 1 inch = 10 lines (“big line”)). The word "inch" was introduced into Russian by Peter I at the very beginning of the 18th century. Today, an inch is most often understood as an English inch, equal to 2.54 cm. - Vika helps us.

Here, by the way, lies the clue to the word three-line - a rifle of the third line - 3x2.54 = 7.62 mm. By the way, in the West they use a special designation with regards to "Russian" cartridges - R. For example, 7.62x54 R - where R = Russian (popularly) or Rimmed (according to the classification).

Rim (from the English ring) is a separate item of ammunition terminology and it tells us either about the type of ignition or the type of extraction of the sleeve.

Many of you have seen rimfire cartridges - the 0.22 LR cartridge - or, in the people, "small".

As for extraction, cartridges of this type (with a rim) are more often revolver cartridges, as well as rather outdated rifle cartridges, for example, 7.62x54R. This cartridge is used to this day in our area and is in service (PK, SVD). Despite the fact that in the West they have long abandoned sleeves of this type, preferring the annular groove.

But back to calibers. So, the Americans use the inch system in the designation of the caliber, so their calibers are usually indicated by the following scheme. Bullet diameter (barrel caliber) in inches and the name of the company that developed the cartridge, or the type of weapon where it is used.

For example, .45 ACP = 0.45 inch (11.43 mm) Automatic Colt Pistol (colt automatic pistol). Automatic in those years called self-loading pistols(compared to single action revolvers). In this caliber, it was necessary to indicate the type of weapon, since the cartridge case of the .45 ACP cartridge differed from the cartridge case of the same caliber for the Colt revolver precisely by the same rim.

308 Winchester - (0.308 inch Winchester cartridge) = 7.62x51 mm - it is noteworthy that many originally hunting cartridges subsequently entered service with NATO, and as army ammunition they were named 7.62 NATO (.308 Winchester) 5.56 NATO (.223 Remington) and etc.

40 Smith & Wesson, .380 ACP and other similar calibers are named after the same pattern. But she's not the only one! And who promised that it would be easy?

For cartridges in the West, there are still many all sorts of schemes and designations. For example, he lived for himself a revolver cartridge. 38 (9.65mm) - he lived and did not know grief. But users began to complain about the low lethality. And twins appeared - .38 Special and 357 Magnum - "the twins look like mugs, only they were successful in growth." Hurry and Magnum - significantly reinforced cartridges in a longer sleeve.

Moreover, sister cartridges calmly entered the old models of .38 caliber revolvers, and when shooting, the bridge of the revolver was often torn to shreds. In this connection, manufacturers began to install a limiter along the length of the sleeve in revolver drums. And indeed, there are a huge number of similar, but different .38 cartridges from Colt, Smith & Wesson and other manufacturers.

What else is indicated on cartridges in the West? Since we started with the rims and primer, let's go further - the type and amount of gunpowder in the cartridge is indicated by markings + P or + P +, etc. These are, as a rule, outwardly identical cartridges, but with much greater muzzle energy. They require careful handling, as not every barrel is designed for them.

They also indicate the type of bullet - expansive, lead, soft nose, tracer, armor-piercing and other fruits of the imagination of cruel people.

Indicate the weight of the bullet in grains - grain (grain) is an old unit of measure based on the weight of the grain. In the modern classification, it is equal to 0.064 grams.

As a result, if on a pack of cartridges we see something like Winchester 9mm Luger 147gr. JHP, we understand that we have Winchester cartridges of 9 mm Luger caliber (9x19) with a heavy expansive shell bullet weighing 9.4 grams.

It is worth noting separately hunting calibers. Almost everyone has heard about the 12th, 16th and other calibers, but few people know what the numbers 12 and 16 actually mean, and why 16 is less than 12. Perhaps someone noticed that in the English marking next to the caliber is the word Gauge (geydzh). So, the gage is an ancient weapon measure that has migrated to us from the time when the width of the barrel was measured in a simple way.

A gage is a lead ball that was passed through the barrel of a weapon to determine the caliber. And the balls were rolled out of one pound of lead. Therefore, if ten even balls are cast from one pound of lead, then a one-ball wide barrel will be 10 gauge, if cast 16 (each ball will naturally be smaller), then the barrel will be 16 gauge. In hunting weapons, these calibers have remained since those times.

The nominal caliber of the 12-gauge barrel is 18.5 mm

Finally, a photo of my collection of cartridges. Law enforcers can relax - the collection is located outside of Ukraine. If you recognize someone in the photo or want to get acquainted, ask.

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 superficially look at the trunk, it may seem that it is just a pipe, almost like a water pipe. And, like all pipes, the barrels of weapons differ in diameters, which, in relation to weapons, are usually called caliber.

What are hunting rifle calibers?

The answer is simple - the diameter of the bore. Correct, but in the first approximation. The fact is that the bore has complex profile. But we will return to this a little later.

We usually say about smoothbore guns: "A shotgun of 12, 16, 20, 28 or 32 gauges." At the same time, we know for sure that a 28-gauge gun has a thinner bore than a 12-gauge. It is clear that these numbers are not units of length.
The nominal value of the caliber (4th, 8th, 10th, 12th, etc.) corresponds to the number of round bullets cast from an English pound of lead.

Not easier with the 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 exactly the same bore diameters.

Shotgun calibers

Let's try to deal with smoothbore weapons first. Now in Russia only five named calibers are produced.

But before, besides them, shotguns of the 4th, 8th, 10th and 24th calibers were produced. The numbers denoting these calibers correspond to the whole number of round bullets obtained 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 having a diameter equal to the diameter of the 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 value of the barrel diameter (in mm) for any caliber. It is equal to 42.5 / (cubic root of the caliber). It is possible to determine the caliber if the diameter of the bore is known;
• The caliber is equal to the third power of the ratio 42.5 / (bore diameter in mm).

History of calibers

Back at the beginning of the last century, all integer calibers were “in use” (4, 5, 6, 7, and so on up to 36). It seems very strange that such an irrational designation of calibers has lasted to the present day.

After all, the 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 the definition of calibers through the number of bullets by barrel diameter, which is obtained not from a pound, but from a kilogram of lead. On French guns of that period, there are occasionally traces of that reform. A 12-gauge shotgun in Napoleonic style was designated 40.

Shotgun channel profile

From the breech, it has a chamber - a nest 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 sleeve not only exposes the bottom of the sleeve to the plane of the breech cut of the barrels, but also centers it in the chamber with the help of a cone. The chamber is a truncated cone, expanding to the breech cut by 0.3 mm. This is necessary for the free extraction of the spent cartridge case.

The length of the chamber must match the length of the sleeve. Longer cartridges lead to unacceptably high pressures of powder gases in the barrel when fired; cartridges that are shorter than the chamber lead to non-uniform scree and harshness and, in addition, spoil the chambers.

Sleeves for shotguns

Our industry produces shotguns for cartridge cases 70 and 76.2 mm long. These dimensions originate from the inch system. In the world, chambers are made from 51 to 89 mm long. The generally accepted norm is that it requires the application of the value of the length of the sleeve in the untwisted state to the finished cartridge.

In addition, when specifying the caliber of a smooth-bore weapon, the length of the sleeve is written through a slash. For example. 12/70 or 20/76. Some hunters have a delusion that in order to easily remove metal cartridge cases from the chamber, they should almost hang out in it. In fact, the brass sleeve in the chamber must sit tightly so that when fired, its deformation does not go beyond the elastic limit. If a free chamber allows the case to reach the limits of plastic, irreversible deformation, it will be very difficult to remove it.

So that a gun can be fired using cartridge cases various designs(with different wall thicknesses), the chamber is followed by a transitional cone or projectile entry. Sleeves made of different materials have different internal diameters of the necks, which differ from the diameter of the bore.

To prevent such a breakthrough, it is necessary that the height of the felt wad be at least one and a half times the length of the transition cone. Its profile is different, but the length rarely exceeds 10 mm. Behind the transitional cone, the actual bore begins, which continues to the muzzle device. IN rare cases when it is not present, the channel without significant change diameter continues to the muzzle.

Thus, the caliber in a smoothbore gun is the internal diameter of the barrel from the projectile inlet to the muzzle device.

Practical difficulties

Now, in theory, everything seems certain, but in practice there are a couple of complications. Any company has its own sizes of tools and equipment for processing barrel bores of each caliber. Even in our country of total standardization, the Tula Arms Plant produces 12-gauge guns with a channel diameter of 18.5-18.7 mm, and a mechanical plant in Izhevsk 18.2-18.45 mm.

Moreover, in practice, 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 is obtained by itself. Any deep hole on the input side of the processing tools is somewhat wider. However, this imperfection also plays a positive role.

Moving from the chamber, the wad, somewhat worn out, still does not stop working (preventing the breakthrough of powder gases) because the diameter of the channel decreases. This reasoning fully applies to both the traditional felt wad and the polyethylene obturator wad.

For the sake of justice, it should be noted that the best gunsmiths make special efforts, and their barrels between the transitional cone and the muzzle device really have a constant diameter, they are a real cylinder.

In addition, sometimes a small cone is made specially on the first third of the channel (from the breech).

Returning to the definition of shotgun caliber, we must understand some convention of this parameter.

Shotguns usually have chokes, the main purpose of which is to finally form the shot sheaf. Chokeless barrels are rare in shotguns, although they tend to shoot better zeros. Such barrels are called "cylinders".

What is a choke and what is it for

The narrowing of the most common form is called "chok".
From the side of the muzzle, it is a cylinder, the length of which is greater, the greater the narrowing.

• The 12 gauge full choke is 18mm long. It mates with the main channel with a sloping conical surface (taper 1:120);
• The length of the cylindrical part of the pay is 10 mm.

Let's first define the concept of "chok".
This constriction of the bore of a shotgun is located near the muzzle. This narrowing is very rarely made more than 40 thousandths of an inch (in the metric system - 1.01 mm). Each "thousandth" can be considered as a narrowing unit.

You can read more about marking checks in the article: "Marking of interchangeable chokes".

The barrels of guns designed for shooting on a round ground 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 side of the muzzle, a “bell” is made measuring 10-15 thousandths of an inch.

Currently, many manufacturers of hunting and sporting weapons complete their weapons with interchangeable chokes, which are light tubes screwed into the barrel from the muzzle. For this, a special key is included in the kit.

Choke shapes

Interchangeable chokes are sometimes made in the form of barrel extensions, usually not exceeding 150 mm.
However, the well-known French company Verneuil Carron made a real revolution by manufacturing a series of barrel extensions for semiautomatic shotguns with a length of 820 mm.

Designation of the size of the chokes

To indicate the size of the chokes, there is different variants(Not yet common standard). One of them is to use sprockets: * - full choke, ** - 3/4 choke, *** - half choke, **** - quarter choke or cylinder.

Other manufacturers use the letter "0" to designate chokes. For example, the company "Beretta" puts the mark "0000" on the cylinder. This means that the barrel is indeed cylindrical. And on the free ends of the interchangeable chokes you can see small risks. And again, one risk corresponds to a full choke.

Choke profiles are different not only for ballistic reasons, but also based on the type of shot. Now the problem of replacing lead shot with steel shot to improve environmental situation on reservoirs where waterfowl are intensively hunted.

However, the use of steel shot requires very smooth transitions in the bores. Otherwise, their catastrophic wear is observed. To prevent this from happening, modern manufacturers of shotguns perform all transitions in bore diameters as hyperbolic.

In addition to the "ordinary" choke, barrels are produced in the world with several other options for muzzle devices.

The complexity and variety of profiles of smooth-bore weapons even of the same caliber must be taken into account when selecting wads, spacers 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" zeros of different designs.

Channel drilling types

Speaking about the calibers of guns, it must be said about two types of channel drilling, which allow you to shoot both shot and bullets at incomparably greater distances than from ordinary smoothbore guns. We are talking about a rifled choke - a paradox and Lancaster drilling, in which the barrel bore has an oval section, “twisted” with a regular rifling step.

Fortunately for our hunters, weapons with such barrels are formally considered smoothbore. This allows you to purchase it under the same licenses as conventional hunting smooth-bore weapons.

Shapes of muzzle devices

Forms of muzzle devices (from top to bottom):

• a) normal conical choke;
• b) choke with pre-muzzle expansion;
• c) a bell with a pre-muzzle constriction;
• d) parabolic choke;
• e) normal bell;
• f) strong choke;
• g) rifled choke (paradox).

IN different countries world, the caliber of a weapon is both designated and measured in different ways: either along the fields, or along the bottom of the rifling of the barrel bore. In addition, the designation of the cartridge caliber can be conditional, for example, small-caliber cartridges. 222 Remington and .22LR have almost the same caliber, but differ in type (the first cartridge is central ignition (primer), the second is rimfire) and case size.

So in the countries former USSR the caliber of rifled weapons by the distance between opposite fields of rifling, in NATO countries - by the distance between the bottom of opposite rifling, the caliber of bullets (shells) - by the largest diameter.

Caliber of rifled small arms in countries using English system measures (USA, UK, etc.), measured in fractions of an inch: in the USA - in hundredths (0.01 inches), in the UK - in thousandths (0.001 inches). In general, calibers are converted on the basis that 1 inch (1") equals 25.4 mm (2.54 cm).

In the inch system, calibers are indicated in hundredths or thousandths of an inch, but without a leading zero, i.e. caliber .50 stands for 0.5 inch or 12.7mm and .30 stands for 0.3 inch or 7.62mm.

In the record, the zero of the integer part of the number and the designation of the unit of measure (inch) are omitted, while in English-speaking countries a dot is used as a decimal separator: .45, .450 In Russian texts, traditional English and American calibers are written in the same way, that is, with a dot, and not a comma, accepted in Russia as a decimal separator: caliber.45 caliber.450, etc.; V colloquial speech: 45 caliber, 450 caliber.

In countries using the metric system of measures ( Russian Federation and all countries of the world except the USA, Great Britain, Myanmar and Liberia), the caliber is measured in millimeters, in its designation, the length of the sleeve is added through the multiplication sign, for example 7.62 × 54 mm. In this case, it must be borne in mind that the length of the sleeve is not a characteristic of the caliber, but a characteristic of the cartridge. Cartridges can be the same caliber, but different lengths.

The following classification of small arms calibers is generally accepted:

Correspondence table for the most common calibers of rifled small arms

Shotgun caliber

For smoothbore guns, calibers are measured in a fundamentally different way: the number indicating the caliber is the number of round bullets for a particular gun, which can be cast from 1 English pound of lead (453.5 g).

In this case, the bullets must be spherical in shape, identical in mass and diameter, which is equal to the inner diameter of the barrel in its middle part.

The smaller the barrel diameter, the more bullets are produced from a pound of lead. Thus, the tenth gauge is greater than the twentieth, and the sixteenth is less than the eighth.

The largest is the first caliber. The diameter of the barrel of a gun of this caliber is 42.42 mm.