Displacement of Fluid by a Bullet
#100515
01/16/2012 6:24 PM
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Gregg Richter
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This slo-mo video shows the spectacular results of a high speed bullet hitting a can of tomato soup. The video was unclear as to whether or not it was an expanding type bullet, and I was unable to tell by looking at the bullet as it exited. Maybe some of you sharper eyed sleuths can. http://www.fieldandstream.com/blogs/gun-nuts/2012/01/high-speed-video-308-vs-soup-canNote that some of the fluid comes back towards the shooter. I first heard about this phenomenon when described by JD Jones as "blow-back," in an issue of the SIXGUNNER a couple years ago. I wish it showed the same shot with say, a .454 cast WFN and a Hornady XTP...
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Re: Displacement of Fluid by a Bullet
[Re: Gregg Richter]
#100518
01/16/2012 6:52 PM
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Joined: Jan 2004
Posts: 259
Shortgun
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According to the box of ammo it is FMJ if they are firing a .308 Win.
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Re: Displacement of Fluid by a Bullet
[Re: Shortgun]
#100522
01/16/2012 7:56 PM
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Gregg Richter
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I saw that ammo also, Shortgun, but don't like to assume it is what they used, but if so, imagine what the results would be if it was a hollow point.
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Re: Displacement of Fluid by a Bullet
[Re: Gregg Richter]
#100525
01/16/2012 8:27 PM
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Joined: Jan 2004
Posts: 4,461
pab1
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Experience is the best teacher, hunger good sauce. Osborne Russell Journal of a Trapper
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Re: Displacement of Fluid by a Bullet
[Re: pab1]
#100526
01/16/2012 8:54 PM
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wapitirod
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I like watching the ballistic gelatin testing since I figure it's the most real world for hunters. I want to do some testing this summer with different loads and calibers while I'm on vacation. I normally go to the middle of no where for vacation and spend my time sleeping and killing rattlers in the evening so I'm going to try and be more productive.
I won't be wronged. I won't be insulted. I won't be laid a-hand on. I don't do these things to other people, and I require the same from them. John Wayne-The Shootist
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Re: Displacement of Fluid by a Bullet
[Re: wapitirod]
#100563
01/17/2012 9:27 AM
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Joined: Dec 2011
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430RUPE
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journeyman
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VACATION? Your always on vacation aren't you? LoL
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Re: Displacement of Fluid by a Bullet
[Re: Gregg Richter]
#100578
01/17/2012 3:18 PM
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98Redline
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Note that some of the fluid comes back towards the shooter. I first heard about this phenomenon when described by JD Jones as "blow-back," in an issue of the SIXGUNNER a couple years ago.
I think what you are seeing is the applied result of Pascal's pressure law. When the bullet enters the soup can, it essentially pressurizes the fluid in the can. When the can ruptures, fluid will squirt out of every available hole to relieve the pressure, pretty much regardless of whether that is forward, backward, up or down.
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Re: Displacement of Fluid by a Bullet
[Re: 98Redline]
#100612
01/18/2012 2:41 AM
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Gregg Richter
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Thanks for sharing that.
So factually and scientifically, even if there is "only an entrance hole," if ENOUGH PRESSURE on the body fluids is generated, there should be blood exiting.
This was shown in a photo accompanying the article I mentioned from THE SIXGUNNER.
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Re: Displacement of Fluid by a Bullet
[Re: Gregg Richter]
#100622
01/18/2012 6:28 AM
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Joined: Jun 2008
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doc with a glock
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Gregg,
He is shooting an M1A in the clip, although in the intro here has an AR. At the end of the clip you see the M1A. Assume it is a 308? Most likely.
Doc
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Re: Displacement of Fluid by a Bullet
[Re: Gregg Richter]
#100629
01/18/2012 12:26 PM
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Joined: Oct 2010
Posts: 738
98Redline
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Shooting a soup can and shooting an animal are two very different things. Some notable things that come to mind are:
1: The soup can has a significantly lower volume than any game animal. This will cause the pressure spike inside the can to be significantly higher than inside the animal and thus the effects of the overpressure to be much more dramatic.
2: Skin and hide tends to be very elastic. It stretches out then returns to shape very well, the metal, not so much. this will allow the hide to expand to soak up the overpressure without a massive pressure related rupture like you have in the soup can.
3: Animals are not solid fluid through and through, things like the lungs and stomach are very compressible which do so to increase the internal volume of the animal and further reduce the pressure spike. The soup can is filled with an incompressible fluid like a hydraulic cylinder.
4: There are all sorts of things that happen in front of and behind the bullet with respect to dynamic pressure waves
So the very long answer is that there are no absolutes with respect to blood trails. If you look at high speed camera images of animals being shot you can see the pressure waves ripple across the hide and/or the body expand to absorb the overpressure condition. The more animals I shoot the more I realize that every single one is different.
While not perfectly scientific, I would think that a better analogy would be to shoot a 3/4 filled 5 gal bucket with the top on and a 2" hole cut in it. The volume would be much closer to the body cavity volume of a deer than is an 8oz soup can and the airspace in the top of the bucket and the hole would allow for compression of the air and venting (similar to the lungs collapsing and air being forced out the mouth and nose). My guess is the results would be not nearly as impressive as the exploding soup can and probably make for a pretty dull video.
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Re: Displacement of Fluid by a Bullet
[Re: Shortgun]
#100633
01/18/2012 2:13 PM
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Joined: Jan 2009
Posts: 9,836
Whitworth
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According to the box of ammo it is FMJ if they are firing a .308 Win. The title clearly states it's a .308. Rifle velocities produce more drama for sure.
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Re: Displacement of Fluid by a Bullet
[Re: 98Redline]
#100634
01/18/2012 2:42 PM
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Joined: Jan 2004
Posts: 9,608
s4s4u
Shootist
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We shoot plastic milk jugs filled with colored water for fun, and you see some equally impressive explosions. I don't equate that to what happens to a deer, but it is a blast to say the least.
Rod, too.
Short cuts often lead to long recoveries.
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Re: Displacement of Fluid by a Bullet
[Re: 98Redline]
#100780
01/19/2012 8:05 PM
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Joined: Jan 2004
Posts: 694
430man
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Shooting a soup can and shooting an animal are two very different things. Some notable things that come to mind are:
1: The soup can has a significantly lower volume than any game animal. This will cause the pressure spike inside the can to be significantly higher than inside the animal and thus the effects of the overpressure to be much more dramatic.
2: Skin and hide tends to be very elastic. It stretches out then returns to shape very well, the metal, not so much. this will allow the hide to expand to soak up the overpressure without a massive pressure related rupture like you have in the soup can.
3: Animals are not solid fluid through and through, things like the lungs and stomach are very compressible which do so to increase the internal volume of the animal and further reduce the pressure spike. The soup can is filled with an incompressible fluid like a hydraulic cylinder.
4: There are all sorts of things that happen in front of and behind the bullet with respect to dynamic pressure waves
So the very long answer is that there are no absolutes with respect to blood trails. If you look at high speed camera images of animals being shot you can see the pressure waves ripple across the hide and/or the body expand to absorb the overpressure condition. The more animals I shoot the more I realize that every single one is different.
While not perfectly scientific, I would think that a better analogy would be to shoot a 3/4 filled 5 gal bucket with the top on and a 2" hole cut in it. The volume would be much closer to the body cavity volume of a deer than is an 8oz soup can and the airspace in the top of the bucket and the hole would allow for compression of the air and venting (similar to the lungs collapsing and air being forced out the mouth and nose). My guess is the results would be not nearly as impressive as the exploding soup can and probably make for a pretty dull video. I need you and your knowledge. This is exactly what I have been saying about different performance. I shoot deer, not soup cans and each bullet, boolit and velocity is different.
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Re: Displacement of Fluid by a Bullet
[Re: 430man]
#100838
01/20/2012 6:23 AM
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Posts: 478
Pasco
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Back in the 1980's when the 7mm mag was all the rage, my buddy shot a mule deer at 120 yards and the entrance hole was twice as big as the exit. The same thing happend to me on a antelope I shot with a 25.06 (rifle) at over 400 yards. I wonder if this is the same thing as the soup can.
Any one else ever had a entrance hole larger than the exit?
Don't confuse shooting with hunting. Shooting is a game, hunting is a sport.
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