When reviewing American films, one often hears about some kind of "45 caliber" pistol. At the same time, many compatriots know that only guns are made in their native spaces with such a caliber. Including anti-tank. How is it that with the same caliber designation, our and American weapons are so different in bore diameter?
The word "caliber" comes from the French "caliber" and denotes the diameter of the barrel of a weapon, which can be calculated using one of the methods. The methodology is determined only by the approach to the issue of a specific manufacturer of weapons and ammunition, as well as the type of weapon in question. For example, in smooth-bore weapons, the caliber is measured simply by the inner diameter of the barrel. For rifled weapons, the caliber can be determined either by the distance between opposite rifling fields (as was done in the USSR), or by the distance between the bottom of opposite rifling (as they do in NATO).
Even ammunition with similar caliber markings can be very different from each other and not interchangeable for the two weapons. The simplest example is the Luger pistol (PL) and the Makarov pistol (PM). Both are in 9mm caliber. However, for the PM it is 9x18 Makarov, and for the submarine it is 9x19 Parabellum. At Makarov, the distance between the grooves is 9 mm, the distance between the bottom of the grooves is 9.27 mm, the diameter of the sleeve is 9.25 mm. Luger's rifling fields are 8.8 mm, the distance between the bottom of the grooves is 9 mm, the diameter of the sleeve is 9.03 mm. This example clearly shows how "identical" ammunition can differ within the framework of the "European school" of weapons.
>>>>Ideas for life | NOVATE.RU<<<<
With the "American-British school" it is even more difficult. Primarily due to the fact that a different measurement system is used there. In the United Kingdom and the United States, inches are used; in continental Europe, millimeters. Thus, it turns out that when Americans and Europeans refer to "45 gauge," they mean completely different things. "Caliber" is a conventional technical designation in the arms business, while in different countries and organizations it is measured in different quantities. In the USA and Great Britain the caliber is measured in inches, in the EU and NATO in millimeters, in the post-Soviet space the caliber is measured in millimeters.
It is important to understand that 1 inch is 25.4 millimeters. Therefore, when Americans say "45 caliber pistol", they simplify pronunciation for the sake of banal convenience, since in fact it is a 0.45 caliber pistol - 0.45 inches or 11.43 millimeters. Moreover, for Europe and the republics of the former USSR, "45 caliber" is 45 millimeters. In other words, the whole confusion arises from the difference in the used measurement systems. It should also be added that due to the specifics of inches, many calibers in the USA and Great Britain are indicated not only in tenths, but even in hundredths. For example, the AR-15 rifle uses .223 Remington or 5.56x45mm NATO cartridges, which are 0.223 inches or 5.7 mm.
If you want to know even more interesting things, then you should read about why pistol bullets are made "dull" and round, and rifle - "sharp" and angular.
A source: https://novate.ru/blogs/250621/59508/
IT IS INTERESTING:
1. Why are cardboard and plywood houses being built in American suburbs?
2. Why do American men wear a T-shirt under their shirt?
3. Will the water protect from shots, as shown in the films?