Why the longer the barrel, the farther the range! ?

Bullets generally have enough energy to adapt to related weapons and meet the requirements of weapons for different targets. Properly lengthening the barrel can make full use of gunpowder energy, improve the range and power of weapons, and also help to reduce muzzle pressure, temperature and noise. Long barrel can also improve aiming accuracy and effective range. However, the barrel should not be too long, otherwise it will increase the quality of the weapon, affect the service use, and the range may be reduced. The short barrel is actually a waste of gunpowder energy, but the pistol is a self-defense weapon that is carried with you, which is small and easy to carry. These factors are more important than saving powder energy. When the trigger of the gun is pulled, the spring pushes the striker at the front end of the bolt to hit the ignition cap, which deforms and burns to ignite the propellant, and the propellant explodes in the shell. Because the four walls of the shell are clamped by the gun bore, the explosive gas can only be ejected in the direction of the warhead, thus pushing the warhead forward in the direction of the muzzle. In order to fit closely with the barrel to increase the range and improve the accuracy, the maximum diameter of the bullet is slightly larger than the caliber of the gun, which is deformed and "squeezed out" from the gun bore under the push of gunpowder gas. The range of the bullet is not only related to the amount of propellant, but also to the length of the barrel. The longer the barrel, the longer the acceleration time of the warhead, so the greater the muzzle velocity and the farther the range. Bullets also wear the barrel a lot. Okay, the running life of the bullet in the barrel is no more than a few minutes. Of course, the running time of the bullet in the barrel is very short. The range of the projectile is determined by "measurement (impulse)"! Momentum refers to the amount of motion of an object, which is determined by its mass and speed. Measurement refers to the quantity of the direction of motion of an object. As long as you are measured, you can shoot far! Physical explanation: instantaneous force is a force with very short action time, which is also called balance force in physics! Theoretically, measurement equals force times action time equals momentum change! So the longer the action time (that is, the longer the barrel), the greater the measurement! But the force of projectile belongs to non-fixed force! Not suitable for equal acceleration! Too long barrel will affect the muzzle velocity and balance of the projectile! The barrel must be determined by calculation! Measured value = force times dt, and force = pressure times cross-sectional area. When the barrel is too long, the pressure decreases and the force decreases. When the barrel is too short, the reduction of action time will also affect the range, so the barrel with appropriate length must be used to play the maximum range of the projectile! Although the long barrel may make the gun eject farther and make the powder burn more fully and gain more kinetic energy, the longer the barrel, the better. The range of the bullet is related to the following aspects: the length of the barrel; The long barrel has a longer range than the short barrel, but the gun is a single weapon. Rationality and operability must be considered when making. You can't ask a class of soldiers to carry a big gun. Modern infantry weapons pursues the rationalization of firepower performance and weight, that is, both firepower and weight are equally important. Gun is the basic weapon of soldiers, and it should not be a burden to soldiers. We can't change the original intention of design because of the pursuit of precision and scope. There is an optimal ratio between barrel and caliber. For example, in the case of a certain caliber, the longer the barrel, the better. As we all know, the longer the barrel is, the greater the friction on the bullet (far greater than the resistance of the bullet flying in the air). It is likely that the scope has been shortened rather than increased. This ratio data should be obtained in actual experiments. For the rifles used by front-line snipers, you can use a gun with a short barrel, which is convenient to carry. In special missions, use large barrels and large caliber guns to destroy enemy facilities. It is said that shooting with a large caliber rifle can completely paralyze infantry radar vehicles. Caliber and caliber determine the size of the bullet. Small bullets can get better initial velocity, while large bullets generally fly longer and have greater destructive power. So now the bullets are of different sizes, designed for different purposes, and used by ordinary soldiers in pursuit of mobility. Practical and simplified, mostly with small caliber rifles. Other factors that affect the distance are the flight environment of the bullet, such as rain and snow, barrel temperature, recoil and so on. Since the distance is affected by so many factors, it is obviously incorrect to consider only one of them (the length of the pipe).