Human beings, as long as they are launched from the tube, will involve a very interesting parameter: caliber.
This parameter looks simple, simply put, it is the diameter of this tube from which the ammunition is fired.
But in fact, the caliber of human body management is indeed a very chaotic and strange story.
There are so many things about Caliber that are not quite consistent with our common sense.
From the definition of caliber, it is known that the inner diameter of the body pipe ** pipe is marked, which is a length concept.
However, many descriptions of caliber do not necessarily use units of length.
In the early days of artillery, there was often a saying that it was a few pounders.
For example, in the Napoleonic era, there were 6-pounder guns, 8-pounder guns.
The pounder guns here are essentially marked by the weight of the ammunition fired by the gun instead of the caliber of the gun.
In the early days, the shells were solid iron balls, and their weight determined the diameter, so there was no problem in using the weight of the shells to mark the size of the gun.
On the contrary, the magnitude of the artillery power is more intuitively felt.
This way of marking was also very confusing in the early days, when the French pound and the British pound were not the same, so the 8-pounder cannon in the French population and the 8-pounder cannon in the British mouth were completely different sizes.
Similarly, there is a difference between spherical and conical shells, so the caliber can be described as varied.
With the advancement of artillery technology, there are other ammunition other than solid ball shells, and at this time the weight of the shell is still used as a caliber unit, which is a bit inappropriate.
So later artillery began to directly use the unit of length to express the caliber.
Because of some Xi inheritance, some pound gun sizes have also been inherited, such as the early 37mm gun, which is the standard British 1-pound gun caliber.
There is also the more classic 88mm gun in World War II, which is essentially the size of a 25-pounder gun.
So, isn't there a way to use weight as a caliber unit now?
No, there is.
In modern times, there is a single barrel, a shotgun.
The caliber of the shotgun is expressed in such a way that instead of the inner diameter of the barrel, the "number" is used.
For example, 12-gauge shotguns, 16-gauge shotguns, etc.
How did this 12th and 16th come about?
This is going back to the time when the British still used weight to represent caliber.
Early guns also used round ** as a projectile, so weight was used to express the caliber size of the gun.
Use one pound of pure lead to make 12 small lead balls of the same size, then the gun that fires this lead ball is a 12-gauge gun.
If a bunch of pure lead makes 16 shot put, then the one who fires this small lead ball is the 16-gauge gun.
As can be seen here, the larger the designator, the smaller its caliber.
Now the most mainstream should be the 12-gauge shotgun, and the caliber of the 12-gauge should be 18 when converted to the metric system4mm。
However, the shotgun is more special, and the same kind of marked ammunition will be divided into several types of ammunition according to the number of shotguns in the warhead, which has nothing to do with the caliber, so I won't go into details.