What's the name of the middle part of the rifle?

Caliber-the inside diameter of the gun and barrel. Rifle weapon refers to the distance between two opposite rifling lines. Caliber is usually calculated in millimeters, guns below 20 millimeters and guns above 20 millimeters.

Rifle-also known as double thread, spiral concave-convex line in the gun bore. The concave part is called the female rifling, and the convex part is called the male rifling. The function of rifling is to make the warhead rotate, so as to maintain flight stability, improve hit accuracy and increase penetration ability. The rifling of our existing weapons is spiral.

Sliding bore-smooth barrel wall without rifling. Smooth-bore weapons can fire shotguns, arrow-shaped projectiles and tail-stabilized projectiles. Gun body axis-an imaginary straight line passing through the center of a gun body (such as a barrel).

Winding angle-the angle between the tangent of any point on the rifling and the parallel line of the barrel axis. Our country's 1954 pistol, 1956 assault rifle and 1953 heavy machine gun all have a winding angle of 5 degrees and 42 minutes.

Winding degree-The winding degree of rifling wound on the barrel according to the winding angle is called lead. The multiple of lead and caliber is called entanglement. The lead of rifle machine gun in China is 240mm, which is about 3. 15 times of the muzzle, that is, the first chord is 3. 15.

Latch mechanism-The latch mechanism of light weapons can usually be used to complete actions such as ammunition supply, ammunition locking, firing, unlocking and shelling.

Acceleration mechanism-the mechanism that accelerates the movement of its mechanism in a certain type of automatic weapon. For example, in weapons with short recoil barrel, except pistols, acceleration mechanism is generally used to transfer part of the energy of the barrel to the bolt.

Locking mechanism-The main function of locking mechanism is to lock the gun bore and resist the shell casing when the weapon is launched, so as to prevent the propellant gas from escaping backwards and ensure the accurate and reliable launch.

Trigger Gravitation-The force required to press the trigger to fire the weapon when it is ready. The trigger attraction should be moderate and too large, which is easy to change the aiming position; It's too small. It's easy to happen.

Trigger holder-generally located under the shell, semi-circular or semi-oval, to protect the trigger and prevent accidents.

Locking clearance-also known as elastic low clearance. After the weapon is locked, when the bolt is close to the locking support surface on the shell and the shell is close to the barrel with inclined shoulder or bottom edge, the distance between the bottom surface of the bullet and the bottom socket plane of the bolt shell is called bottom clearance. If the bottom plane of the bullet is close to the bottom plane of the bolt hole, the distance between the locking support surfaces on the bolt housing is called locking gap.

Air duct-a tube connected to the barrel of an air-guided weapon with a piston inside. One end of the piston rod is connected to the movable machine. When launching, the bullet passes through the air duct in the hall, and the gunpowder gas escapes from this hole, pushing the piston to complete the automatic circulation action.

Air guide hole-a small hole in the barrel of an air guide weapon, through which gunpowder gas flows into the air guide pipe to push the piston to complete various actions.

Mechanical sight-generally refers to the metal sight used in machinery, such as ruler, sight, measuring hole, etc. The English term word face is an "iron anchor", which is relative to the optical sight.

Ink hole sight-metal sight. Usually, there is a small ink hole on the gauge of this kind of sight to aim at the target with the sight.

Optical sight, also known as optical sight, is an aiming device made by using optical principle, which consists of lens, mirror body and lighting device.

Infrared sight-an instrument that illuminates a target with a near-infrared light source, and the target reflects infrared light, which is converted into photoelectric images and aimed at at night. It consists of infrared searchlight, photoelectric transformer, sight and power supply.

Gun air defense sight-an annular retractable sight, mainly used for shooting air targets, consists of a base and front and rear sights.

Low-light-level night vision device-an out-of-night sight with an image intensifier as the core device. It uses the reflected light of the target under weak light to enhance the visible light image that can be felt by human eyes on the screen, and can observe and aim at the target without infrared probe lamp when working.

Portal sight-consists of portal and sight, used for aiming when shooting. According to the shape of the door, there are: semicircle, rectangle, triangle and so on. Sights also have different structural forms such as rectangles and triangles.

Aiming disk-a hard disk with a bull's-eye in the middle and a small hole in the bull's-eye, and then hung on a stake for training and aiming.

Slot-also known as "camera door", is a part of the aiming device, usually located on the scale, with square, triangle, semicircle and circle. It forms the aiming baseline with the aiming sight.

Sight-part of a sight device. Usually at the upper end of the muzzle. There are several kinds, cylindrical, triangular and rectangular. It supplements the gap of the ruler and forms the aiming baseline. Some can be corrected by moving in the direction and height.

Normal Scale-Same as Scale "3". It is usually indicated by "II" or "D" on the dashboard. When it is too late to measure the distance and change the scale to distinguish, you can directly aim at the lower part of the target with the ordinary scale to shoot.

Sight bar-a benchmark, as an auxiliary aiming point, to determine the correct direction angle and height angle of the gun. This term is used for artillery firing.

Photoelectric rangefinder, also known as light speed rangefinder, is an instrument for accurate ranging with modulated light waves. The measuring range can reach about 25 kilometers, and it can also be used for night work.

Infrared rangefinder-an instrument that uses modulated infrared light to accurately measure distance. The measuring range is generally 1-5km. Laser rangefinder-a precision ranging instrument with laser as light source. If the laser is continuously emitted, the distance can reach about 40 kilometers, and it can be operated day and night. If the laser is pulsed, the absolute accuracy is generally low, but it can achieve better relative accuracy when used in long-distance ionization measurement.

Microwave rangefinder-an instrument that uses microwave as a carrier to accurately measure distance. The operation is simple, the ranging accuracy is high, and the ranging distance is greater than 10 km.

Hammer-a component used to strike the end of an injection to advance the primer of a bullet. There are two kinds of hammers: rotary hammers and straight hammers.

Hammer shaft-the shaft pin that fixes the hammer in a certain position of the weapon, on which the hammer can rotate.

Hammer wrench-the wrench-shaped solid ear exposed on the hammer is a small lever, which is convenient for moving the hammer by hand.

Hammer support-a part of the launching mechanism to support the hammer.

Small grip-the handle under the rifle is similar to the pistol grip, and the shooter can hold it with eleven hands. The small grip never gets close to the shoulder-fired weapon, which increases the support, reduces the recoil effect and improves the shooting accuracy.

Grip-the part of a firearm that can be held by five fingers. It is called the grip of pistols and revolvers, and the small grip of rifles and muskets.

Small grip sleeve-a sleeve installed on the small grip of rifles and muskets to protect the edge and bottom of the small grip from collision. The small grip sleeve can be used to lengthen and strengthen the small grip.

Nameplate of the grip-The grip shows the manufacturer's design or inscription, usually a shield-shaped metal plate. Leather case-a leather case made of leather or other tough materials, which can hold pistols or revolvers. Holsters are usually hung on belts, shoulder straps or saddles.

Gun clothing-The gun is covered with a cover made of leather, canvas, treated cloth, plastic cloth or other weatherproof and sun-proof materials to prevent dust, sand, sun and rain forest.

Gun cabinet-a cabinet for storing light weapons or exhibits.

Gun rack-a shelf for storing guns or exhibitions.

Barrel life-generally refers to the amount of ammunition that a weapon can launch before it loses its ballistic performance.

Note: barrel life is usually measured by the following three methods:

1. Increase of radius of dispersion circle-Generally speaking, when the half diameter of the circle containing 50% of the total number of impacts at the shooting distance 100 meter is 2-2.5 times that at the beginning of shooting, the life of the barrel is over.

2. The number of elliptical holes at the impact point-when shooting at the main target at a distance of 100 meters, the ratio of the long axis to the short axis of the bullet hole on the target is greater than 1.2, which can be considered as elliptical holes. When the oval hole of small caliber firearms reaches 20% and the oval hole of large caliber firearms reaches 50%, the barrel life is considered to be over.

3. When the muzzle velocity drops beyond the allowable value-generally allowable value, it is 50% for small caliber firearms and 10% for large caliber firearms, which means that the service life of the barrel has passed.

Chrome plating of barrel-from the barrel bore, the inner surface is plated with a chromium layer of 35-440 microns. The higher the temperature rise, the thicker the chromium layer should be. This is the main method to improve the life of the barrel at present.

Barrel shape-some other parts are often combined with barrel shape as needed. Such as quasi-constellation, ruler seat, bayonet seat, air guide hoop, air sleeve, handle, etc. In order to facilitate processing and control the wall thickness difference, and to avoid irregular protrusions on the outside, the outside of the cylinder is often designed as a revolving body.

Barrel tail-usually connected with sleeve or socket. The shape of the end face of the tail is related to the types of locking mechanism and shell withdrawing mechanism. The end face of the barrel and the axis of the bore are the main design criteria of the bore. In order to bear the impact of the bolt, and to ensure the strength when launching after reducing the outer diameter of the barrel, and reduce the wear of the muzzle of the barrel, the tail of the barrel is often partially quenched.

Muzzle shape-Muzzle shape has a great influence on the firing accuracy of weapons. The geometric shape of the muzzle must be regular and symmetrical, and the end face should be perpendicular to the axis of the muzzle, so it is not easy to be bruised in service.