08-08-2011, 05:42 PM
The velocity "crack" of 5.56 is noticeably more audible to people than larger calibers. I think that sound falls in the range that humans seem to pick up on more readily.
To me it has two components...There is a sound pressure wave that you feel, and one that you hear. 5.56 has almost NO felt sound pressure, while the audible signature is very distinctive. I shot a match Saturday, and I could easily differentiate the .308 rounds I was pulling from the 5.56 rounds on the target next to me, and it wasn't because of where I was. I was actually pulling and marking my target, plus a .300 WinMag target between my .308 and the .223, so I was standing in the middle by the .300 WinMag target with my target to my left and the 5.56 to my right. It was easy to hear which was 5.56 and which .308. (The guy shooting the .300 WinMag was regularly giving us a dirt shower shooting into the berm above us, and his rounds were tumbling at 600, causing the "bumblebee" sound. There was something definitely wrong with his rifle.)
To me it has two components...There is a sound pressure wave that you feel, and one that you hear. 5.56 has almost NO felt sound pressure, while the audible signature is very distinctive. I shot a match Saturday, and I could easily differentiate the .308 rounds I was pulling from the 5.56 rounds on the target next to me, and it wasn't because of where I was. I was actually pulling and marking my target, plus a .300 WinMag target between my .308 and the .223, so I was standing in the middle by the .300 WinMag target with my target to my left and the 5.56 to my right. It was easy to hear which was 5.56 and which .308. (The guy shooting the .300 WinMag was regularly giving us a dirt shower shooting into the berm above us, and his rounds were tumbling at 600, causing the "bumblebee" sound. There was something definitely wrong with his rifle.)
You seek escape from pain. We seek the achievement of happiness. You exist for the sake of avoiding punishment. We exist for the sake of earning rewards. Threats will not make us function; fear is not our incentive. It is not death that we wish to avoid, but life that we wish to live. - John Galt