#Decibels for 300 blackout subsonic vs supersonic crack

If the sensor is set a few feet from the muzzle at a right angle to the line of departure, the pressure wave from the sonic crack will be less than if the sensor was directly down range.Īlthough I find supersonic rounds out of a suppressor are still uncomfortably loud, it's much quieter than shooting without a suppressorĭocGKR, thank you for posting that link. How much sound reduction a suppressor will give also is dependent on many variables and one of the most important, when comparing performance, is the location and type of the sensor. But the sound of each wave varies in tone and sound pressure according to many variables, such as velocity, size and shape of the object, humidity, pressure altitude and so on. I don't know how many decibels the sonic crack produces. If a sniper were to make such a shot, a listener could follow the line of the sound back to the shooter. allowing the listener to track the path of the bullet by ear. If a bullet were to be fired parallel to a row of telephone poles, for example, a listener would hear the sound of the sonic wave hit the poles and reflect. You can hear the crack reflect off of objects as the bullet passes by. You will only hear the sonic crack when the wave passes over you. The pressure wave from an object traveling at supersonic speeds is constant, just like the bow wave of a ship traveling through water. I realize this part is mostly an academic question. Does it occur just at the point the bullet breaks the sound barrier or does a supersonic projectile continue to make noise as it travels? I always assumed it just occurs once as the sound barrier is broken. It will still be loud because of going supersonic - but perhaps in the upper 120 dB range? Or does the sonic crack take it well over that?ĭo suppressor manufacturers noise level ratings take the sonic boom/crack into account?Įven target pullers at Camp Perry have to wear earpro when working the pits - this makes me wonder how the sonic crack works. I would expect suppressed 300 BLK from a 16' barrel to produce slightly less noise than 5.56 because all the powder will have burned up inside the barrel.

I plan to use earpro when shooting anyway, but am trying to gauge how damaging it might be if I ever have to shoot non-suppressed. This suggests the noise from the bullet breaking the sound barrier may be less than some suggest. On their web page, SilencerCo rates this suppressor at the following noise levels at the muzzle:ģ00 BLK - 119.5 dB (my assumption is subsonic ammo) I bought a SilencerCo Omega for my gun which was just recently approved by the ATF (yay!). Some people say just the sonic crack will register 140 dB, which is right at the OSHA-stated hearing safe threshold (and I don't consider that hearing safe, especially for people like me who have hearing damage). Obviously there will be more noise with supersonics, but I have read conflicting information about just how much. My question is around the combination of a suppressor and supersonic ammunition. At this point there might be one or two ammo offerings out there that provide reliable expansion at subsonic velocities but choices are limited. However, I am still on the fence about using subsonics in a defensive role. I own a 300 BLK AR and I get that one of the driving things behind the cartridge is the use of subsonic ammunition in an AR-platform carbine.