Yes. There are two common silencers: one is installed on the muzzle, and the other is integrated with the barrel. In the first type of muffler, the muffling principle is that the gunpowder gas in the chamber flows out of the muzzle and gradually decelerates through the hole of the muffler, thus greatly reducing the muzzle noise. Since there is a certain error in the coaxiality between the hole of the additional silencer and the inner bore of the barrel and cannot completely overlap, the bullet is affected when passing through the hole of the silencer from the barrel, thus affecting the shooting accuracy to a certain extent. In the second type of silencer, there is a transverse exhaust hole in the front of the barrel, and on the outside is the sleeve. The sleeve forms an expansion chamber, and gunpowder gas flows into the expansion chamber through the transverse exhaust hole. This integrated muffler device helps ensure the shooting accuracy of the weapon.
No matter what kind of silencer, it can only reduce the noise generated by the gunpowder gas, but cannot reduce the noise generated by the warhead shock wave. If the warhead flies at supersonic speed, the effect of the silencer is very limited, so micro-acoustic weapons should use subsonic bullets (at 0°C, the speed of sound in dry air is 331m/s, subsonic refers to the speed of the bullet lower than 331m /s——Editor’s note).
So, can the noise reduction effect be achieved without a muffler? In fact, if you can prevent the gunpowder gas from ejecting from the barrel, you can reduce the muzzle noise. In 1901, J. Hutflis applied for patent number 5478 in Austria, which eliminated weapon noise and recoil by adding a piston to the gun/bullet. He made the bore at the front of the barrel the same size as the bullet diameter, and the bore at the rear of the barrel the same diameter as the cartridge case. He then installed a piston in the cartridge case. When shooting, the piston pushed the warhead forward. When it advanced to the gun When the tube is reduced in diameter, the piston is stopped, while the warhead continues to fly forward alone. There is a small hole in the barrel behind the piston, and the gunpowder gas is slowly released through the small hole. According to this plan design, after each bullet is fired, a purge bar must be used to push the piston out of the barrel from the rear.
By preventing the flow of gunpowder gas to achieve the purpose of silencing and extinguishing flames, the Soviet Union carried out bold practices in this field. At the end of the last century, the PSS pistol series launched by the Soviet Union was based on this principle. Different from the patent mentioned above, the piston of the bullet used in this gun is blocked in the cartridge case, which eliminates the cumbersome action of ejecting the piston from the barrel.
The bullet used by the PSS silent pistol is called 7.62×41.5mm SP-4 bullet. 41.5mm represents the length of the bullet case. The propellant of this bullet is located under the light metal piston, and the sharp point in the center of the piston is inserted into the bottom of the warhead to position the warhead. The warhead is made of steel with a brass guide at the front. The cartridge case is made of copper-plated steel plate. The primer is installed in the base of the bullet to ensure that it will not be ejected under the pressure of gunpowder gas.