The caliber of a smoothbore weapon is the inner diameter of the barrel, the caliber of a rifled weapon is the distance between the rifling fields. It is measured in millimeters, less often in fractions of an inch, depending on the country. In Russia, the caliber is measured in millimeters, in the United States in hundredths of an inch, in England in thousandths of an inch.
The unit of measurement of caliber varies not only depending on the country, but also on the type of weapon. For rifled, these are millimeters, fractions of an inch. For smoothbore, the old English system is used, where the caliber is determined by the number of round bullets of a particular diameter that can be cast from a pound of lead. And the higher the caliber value of a smoothbore weapon, the more bullets can be made from a pound of lead and the smaller their diameter will be.
Weapon calibers can be roughly divided into 3 groups:
- small caliber - less than 6.5 mm, this is a special or sporting weapon;
- medium, or normal, caliber is the most common type of weapon, from 6, 5 to 9 mm;
- large caliber - from 9 mm to 30 mm, this is a special weapon and armament for technical equipment.
Small arms have a caliber of up to 30 mm, from 30 mm - small-caliber artillery. Small arms use cartridges, artillery uses shells, but there are exceptions to this rule: a heavy American sniper rifle with a caliber of 20 mm is loaded with shells, and aviation weapons with a caliber of 23 mm are called a cannon. All weapons with a caliber of 30 mm, according to special literature, belong to small arms and devices are not made for them that absorb the recoil characteristic of artillery.
Small caliber
Small caliber for smooth-bore weapons is 28, 32 and 410, for rifled weapons - from 4 to 6 mm.
A sporting weapon with a small caliber is called a rifle, and a hunting rifle is called a carbine. There is no variety in the design: a bolted bolt of a simplified type and an emphasis on the stem of the reloading handle instead of a combat stop are used, since the cartridge has low power. There are self-loading models based on the principle of free shutter recoil, there are models with accelerated manual reloading.
In addition to hunting, small-caliber weapons are used in sports shooting and in combat. The latter may seem surprising, but for military purposes, a small caliber is attractive because of the accuracy of the hit and the characteristics of a bullet, which has a low energy. But most often such weapons, of course, are used by hunters.
Small-bore hunting carbines are subdivided into:
- Commission - old weapons, TO316 and TO317 carbines. The first is single-shot, the second is equipped with a magazine for 5 rounds. An optical sight with the TO318 index can be attached to TO317. However, such a weapon has a drawback, namely, a Mosin-type fuse, inconvenient in hunting. On weapons with index 01, this drawback has been eliminated, but the barrel is more rigid, the design of the bolt and fuse has been changed, and the calculation for other sights is The entire TO3 line is not suitable for rimfire cartridges, with one exception - model TO378.
- Shop - these are revolving carbines, in fact, even small-caliber revolving guns. Fire from them can be conducted in manual reloading mode and in self-cocking mode. The weapon is light, small in size, its total length is suitable for the extreme value allowed by law. Suitable as a survival weapon.
- Self-loading, which work on the principle of free breechblock recoil, and also have a magazine for 8 rounds, light weight, compactness - the weapon can be quickly disassembled by placing the barrel and receiver in a hollow butt. Such a weapon can float and an optical sight is installed on it.
Medium caliber
Normal or medium caliber for smoothbore weapons is 16, 20 and 24, but the latter are not produced much. For rifled weapons - from 6 to 8 mm. Medium-caliber rifles are used in sports shooting, carbines - in hunting. Incidentally, this category includes the 30th, the most popular caliber used in AK and other Russian carbines.
For combat purposes, medium-caliber weapons are also widely used: they are the main ones among law enforcement officials and the military. Most often, they use 308 (7.62x51 NATO), it is good for sniper purposes, a lot of sniper weapon chambers cut into it.
Large caliber
The large caliber for smooth-bore weapons is 4, 8, 10 and 12, but 4 and 8 are not mass-produced, and 10 are produced in small numbers only in a few countries. Of the large-caliber smooth-bore weapons, 12 gauge prevails in the world. For a rifled weapon, a large one is 9 mm and higher. And the most widely used rifles are 9 mm caliber (9, 3 mm rifling) chambered for:
- 9x53;
- 9, 3x64;
- 9.3x74, etc.
Calibers 9, 53, 10, 75 and 11, 43 are produced in smaller quantities.
Large-caliber weapons are used in combat operations, less often for hunting. This is a weapon with great weight, strong recoil, powerful cartridges, very impressive dimensions. Not every body armor can withstand a direct hit from this, it's not for nothing that large-caliber weapons are called "pocket artillery".
Large caliber bullets have a high stopping and often penetrating effect. And the cartridge for the South African Truvelo SR sniper rifle is, in fact, a projectile, since it was originally used for firing anti-aircraft artillery installations.
Some types of large-caliber weapons, like the Kord machine gun, were specially designed to combat lightly armored targets, and in addition to infantry, there are also tank versions.
Are cartridges of the same caliber different?
There is a difference. The caliber gives information about the bullet, but it does not say anything about the sleeve. And cartridges of the same caliber can have bullets with the same diameter, however, the power, casings and gunpowder sheds will be different.
And to avoid confusion, cartridges are named differently, using different numerals for bullets with the same caliber. If the third digit is indicated in the value after the decimal point, then it does not give information about the bullet diameter, but indicates the difference in the cases.
Often, along with the caliber of the bullet, the height of the sleeve is also indicated, for example: 9x18, 9x21, 9x23. The 9 mm caliber is widespread, so much so that there are several cases with a height of 18 mm, and they are different. And to avoid confusion, they are called 9x18 Mak, 9x18 Ultra. Those. the difference is indicated not only by numbers, but also by letter designation.
Thus, the same cartridge with the same caliber can have several different names, like 9x18 Mak - a cartridge for a Makarov pistol in America.
