PBS and PBS-1 silent firing devices are multi-chamber expansion silencers with a cut-off (obturation) of powder gases. PBS-1 is screwed onto the end of the barrel of AKM assault rifles.
Silencers, PBS and PBS-1 silent firing devices, device and principle of operation, muffler operation scheme.
The structural silencer PBS-1 is designed in such a way that the rubber seal is close to the muzzle. Gunpowder gases ahead of the bullet exit into four small-diameter openings made at such an angle into the expansion chamber that the flow is directed into the space formed by the bottom and the chamber wall. Reflecting and scattering gas jets, these holes reduce their flow rate.
Silencer device, silent firing device PBS-1.
Scheme of operation of a silencer, silent firing device PBS-1.
Further, the powder gases under pressure are vented into the surrounding space through four small openings located inside the housing. The holes communicate with the external environment by a narrow slit 0.2 mm wide. The gas jet, striking first at the wall opposite the hole, is reflected from it and goes outside.
Powder gases, cut off by a rubber stopper, create a pressure sufficient for automatic weapons to work, compensating for the weakened charge of the subsonic special US cartridge used with PBS-1. A bullet, breaking a hole in a rubber stopper-plug, passes through the holes of eleven expansion chambers. Powder gases that burst after the bullet until the rubber closes lose their speed and pressure, passing sequentially through the expansion chambers.
The shutter is crimped with a metal clip, which should protect it from swelling during operation and facilitates replacement. The data on the resource of one shutter during firing with PBS is very contradictory. The values are indicated from 20-30 shots to 100 and even 200. After 20-30 shots, the effectiveness of jamming PBS begins to fall noticeably.
Structurally, the PBS-1 silencer went through two stages of creation. Initially, the PBS device for the AK assault rifle included a housing, on the back of which a head was screwed. The casing consisted of two half-cylinders pivotally connected by axes in the front. The head fastened the half-cylinders, while the twelve jumpers made in the cavity of each half-cylinder formed transverse partitions with holes for the passage of the bullet.
The head, including the obturator with a rubber stopper in the cage, the nozzle at its base had an internal thread for attachment to the muzzle of the barrel, and a disk spring prevented self-screwing. The design of the PBS enclosure was easy to manufacture and maintain, but did not provide proper tightness. Since 1962, the design of the PBS enclosure became non-detachable; a separate separator inserted into the enclosure was also introduced.
The separator was assembled on three longitudinal rods fastened by the front and rear rings. Ten partitions were attached to the rods, and sleeves worn on the rods kept them from displacement. The rings and partitions had openings for free passage of the bullet. The device received the PBS-1 index.
Shooting from an AKM assault rifle with a PBS-1 silent shooting device.
The PBS-1 silencer is very effective, the sound level of a shot is reduced by 20 times. For example, a 7.62 mm AKM assault rifle equipped with one of the PBS-1 modifications shoots no louder than a 5.6 mm sports rifle. Checking the battle and shooting of weapons is carried out after the installation of the next shutter and the production of several shots to form a bullet channel.
As the shutter wears out, the mid-point of contact shifts due to a change in shot conditions. Since the ballistic characteristics of the US cartridge bullet are significantly different from the ordinary ones, the aiming strip of the sector sight of the AKM assault rifle was replaced by a special one with a clamp and completely adjustable in direction. Depending on the installation of the clamp heads, the bar was used for firing a US bullet or an ordinary cartridge.
Based on the book Devices for reducing the sound level of a shot for automatic weapons.
Konovalov N.A., Pilipenko O.V., Skorik A.D., Kvasha Yu.A., Kovalenko V.I..