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. Measured in millimeters, less often in fractions of an inch, depending on the country. In Russia, the caliber is measured in millimeters, in the USA in hundredths of an inch, in England in thousandths of an inch.
The unit of caliber varies not only depending on the country, but also on the type of weapon. For rifled - it's millimeters, fractions of an inch. For smoothbore use the old English system, where the caliber is determined by the number of round bullets of a specific diameter, which can be cast from a pound of lead. And the greater the caliber 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 divided into 3 groups:
- small caliber - less than 6.5 mm, it is a special or sports 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, it is a special weapon and armament for technical means.
Small arms have a caliber of up to 30 mm, from 30 mm - small-caliber artillery. Small arms use cartridges, artillery - 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 do not make devices for it that absorb recoil characteristic of artillery.
Small caliber
Small caliber for smoothbore weapons is 28, 32 and 410, for rifled weapons - from 4 to 6 mm.
A small-caliber sporting weapon is called a rifle, and a hunting rifle is called a carbine. There is no variety in design: a bolt lock of a simplified type and a stop of the stem of the reloading handle are used instead of a combat stop, since the cartridge has a small power. There are self-loading models, based on the principle of recoil of the free shutter, there are models with accelerated manual reloading.
In addition to hunting, small-caliber weapons are used in shooting sports 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 that has low energy. But most often such weapons are, of course, used by hunters.
Hunting small-caliber carbines are divided into:
- Commission - old weapons, carbines TO316 and TO317. The first is single-shot, the second is equipped with a magazine for 5 rounds. You can attach an optical sight with TO318 index to TO317. However, such a weapon has a drawback, namely, a Mosin-type fuse, inconvenient in hunting. On weapons with an index of 01, this drawback is eliminated, but the barrel is more rigid, the design of the shutter and fuse is changed, the calculation for other sights. The entire TO3 line is not suitable for annular ignition cartridges, with one exception - the TO378 model.
- Magazines are revolver-type carbines, in fact, even small-caliber revolver guns. Fire from them can be conducted in the manual recharge mode and in the mode of self-charging. The weapon is light, small in size, its overall length is suitable for the extreme value permitted by law. Suitable as a weapon of survival.
- Self-loading, which work on the principle of recoil of a free shutter, and also have a magazine for 8 rounds, low weight, compactness - weapons can be quickly disassembled by laying the barrel and receiver in a hollow butt. Such weapons can float and an optical sight is mounted on it.
Medium caliber
The normal or medium caliber for smoothbore weapons is 16, 20 and 24, but the latter are few. 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, most popular caliber, which is used in AK and other Russian carbines.
For military purposes, medium-caliber weapons are also widely used: they are the main among the representatives of law enforcement services and the military. Most often, they use 308 (7.62x51 NATO), it is good for sniper purposes, a lot of sniper guns crashes under it.
Large caliber
A 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 in only a few countries. Of the large-bore smooth-bore weapons in the world 12 caliber prevails. For rifled weapons, large is 9 mm and higher. And the most widely used guns of caliber 9 mm (9.3 mm rifled) for cartridges:
- 9x53;
- 9.3x64;
- 9.3x74, etc.
Gauges 9.53, 10.75 and 11.43 are produced in smaller quantities.
Large-caliber weapons are used in military operations, less often for hunting. This is a weapon with a large weight, strong recoil, powerful ammunition, very impressive dimensions. Not every body armor can withstand a direct hit from this, and it is not in vain that large-caliber weapons are called "pocket artillery".
Large-caliber bullets have a high stopping, and often punching effect. A cartridge for the South African sniper rifle Truvelo SR, in fact, is a shell, since it was originally used for firing anti-aircraft guns.
Some types of large-caliber weapons, such as the Kord machine gun, were specially designed to combat the lightly armored target, and in addition to the infantry, they also exist in the tank version.
