Quote of the day–ErnestThing

When a bullet passes through air, it creates a high pressure area in front of, and around it, and creates a slight increase in temperature as the bullet impacts the molecules in the air. The pressure and temperature difference creates enough of a disturbance to bend light slightly. The result is a what appears to be a wavy donut that enters the bottom of your field of view, arcs upward above the target, and drops down into the target. (I call it a “wavy donut,” JD calls it the “undulating donut of death.” I like his better.)

Seeing this phenomenon with my own eye was really amazing. I knew how rifles worked, I knew the physics involved, I knew the trajectory was parabolic, and I’ve seen many charts of bullet flight path; but it’s still hard for your brain to wrap around the idea of a tiny thing flying through the air at 2800 feet per second. Actually seeing it happen seemed to dispel the magic the non-logical part of my brain was convinced was involved. Squeezing a trigger here, didn’t just make something happen there; it began a very simple set of physical principals that ended in a predictable manner that I could view with my eye.

Plus, it was wicked cool.

ErnestThing
May 11, 2009
Boomershoot 2009
[Yup. It’s wicked cool alright.

On the longer shots you can see the bullet arc up above the target and the wind push it off to the side. Then, if you called the range and wind doping right you are rewarded with seeing that wavy donut drop into a little white box on the hillside and transform it into a red flash and a cloud of water vapor 20 feet tall. You and your partners are in the middle of whoops of joy when the boom hits you. The boom is a deep earth shaking sound that video cameras and sound equipment somehow cannot adequately capture with enough fidelity to duplicate the thump to your chest you feel when you are there live.

There are still two positions available at Boomershoot 2010. They are positions #2 and #4. Even though they are in the “.50 Caliber Ghetto” smaller caliber shooters may use them with the restriction that the tree line targets are not available. Sign up here.–Joe]

9 thoughts on “Quote of the day–ErnestThing

  1. It really does have to be experienced. No recording will ever match the reality of feeling that shockwave pass through you.

  2. “…cameras and sound equipment somehow cannot adequately capture with enough fidelity…”

    For one thing, you need a pretty powerful, high quality amplifier and speaker system and the volume has to be cranked way up to get the full dynamic range. Your average video camera has a miniature electret condenser microphone which doesn’t capture the low frequencies very well, and they almost always have built-in AGC, or compression, which ruins the effect, plus the mics themselves can be forced into a mechanical copmpression (reaching the limits of their physical travel) with the high pressure levels. Standing 400 yards away watching “cleanup” without ear protection is enough to hurt the ears, but not terribly, or about what you experience at a very loud rock concert. With a sound system capable of cleanly recreating loud rock concert levels (at least 110, to 120 dBa with tons of power at the low end) and a professional quality, high dynamic range recording system, you’ll come very close to what you experience while standing there.

  3. I was pretty sure that Ry was full of shit and pulling m leg when he told me about seeing the bullet through a spotting scope. There just isn’t any way that something going 2500fps could be seen by my crude human eye once it’s an eyelid blinking distance away. But there it was. The geeky science nerd inside of me went nuts.

    Guns are magic. Just like magic it’s amazing and unreal, until you find out it’s just science and slight of hand. Though I’m not sure guns and munitions will ever be anything but magic to me, no matter how well I understand them.

  4. If you want the trajectory to be really visible, try tracers. Very educational, I highly recommend it (assuming you have the sense to not torch the place…). But the visibility with just the shock/pressure/vapor stuff is really something.

    With tracers you can see just how steep a hill is required to stop a round. Ever skipped stones? Same thing with bullets. Watch it.

  5. It truly was something that I thoroughly enjoyed being able to see through the spotter scope. I also appreciate how difficult a spotter’s job can be as a result of this.

  6. My first experience with that “wavy donut” was during a Mark-19 Range in Korea.

    For those who don’t know, the Mark-19 is a 40mm grenade automatic machine gun.

    Anyways, I was about 500 yards away from the firing point, and I could watch and follow the rounds travel through the air until they hit their target. I took two or three shooters until I recognized what I was seeing. And my thought at the time was “Oh, that is so damn cool……”

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