Subsonic ammunition and resulting Sonic Signatureretro02_02 wrote:Вы имеете ввиду subsonic?nightmare2 wrote:А кто-нибудь пробовал тихие 22 патроны?
Насколько они тихие?
Из гаража будет слышно?
Если и будет слышно,то как из воздушки.
In weapons firing supersonic bullets, the supersonic bullet itself produces a loud and very sharp sound as it leaves the muzzle in excess of the speed of sound and gradually reducing speed as it travels downrange. This is a small sonic boom, and is referred to in the firearm field as "ballistic crack" or "sonic signature." Subsonic ammunition eliminates this sound, but at the cost of lower velocity, resulting in decreased range and lessening effectiveness on the target. Military marksmen and police units may use this ammunition to maximize the effectiveness of their silenced rifles. While the range may be decreased when using subsonic rounds, this may be acceptable for specialized situations, where the absolute minimum amount of noise is required.[22]
However, the numeric effectiveness of subsonic rounds is, again, misrepresented by media. Independent testing of commercially available firearm suppressors with commercially available subsonic rounds has found that .308 subsonic rounds decreased the volume at the muzzle 10 to 12 dB when compared to the same caliber of suppressed supersonic ammunition.[14] When combined with suppressors, the subsonic .308 rounds metered between 121 and 137 dB.
This ballistic crack depends on the speed of sound, which in turn depends mainly on air temperature. At sea level, an ambient temperature of 70 °F (21 °C), and under normal atmospheric conditions, the speed of sound is approximately 1,140 feet (350 m) per second (347 m/s). Bullets that travel near the speed of sound are considered transonic, which means that the airflow over the surface of the bullet, which at points travels faster than the bullet itself, can break the speed of sound. Pointed bullets which gradually displace air can get closer to the speed of sound than round nosed bullets before becoming transonic
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