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Army Tests Dimpled Bullet
08 April 2009, 02:14
Roll-CrimpArmy Tests Dimpled Bullet
This is way up there on my "wow" scale!
It seems that w/ input from Berger Bullets, the guys in green from Aberdeen have a real break through (eh, rcamuglia?
) in bullet design by dimpling the jacketed bullet surface to reduce boundary layer turbulence and friction to significantly up performance. Link to article in Accurateshooter.com
U.S. Army Team Tests Radical New Dimpled Bullet Varmint shooters will be interested in the explosive terminal ballistics for larger bores.
08 April 2009, 02:17
bja105Are they white and spherical?
Jason
08 April 2009, 02:52
SR4759Classified core material?
Give us a break!!
08 April 2009, 03:40
OzzieYou might want to check the date on the report.
08 April 2009, 15:51
303Guyquote:
April 1, 2009
Aaaah... no! Not another one!
Regards
303Guy
08 April 2009, 16:11
hawkinsYears ago George Herter was pushing dimpled
shot for better ranging. Of course many days
with George were april 1.
Good luck!
08 April 2009, 17:50
onefunzr2"Bullet velocities were measured with advanced Doppler Radar."
That was the first sign to me that the article was bogus.
09 April 2009, 05:03
CMcDermottThe Army does have a special millimeter band radar that can track a bullet. Used mostly to track artillery shells (both for aim and for counter-fire) it does have the capability to track individual bullets. One of the first public demonstrations was a re-creation of the Billy Dixon 1500 yard shot from Adobe Walls Indian battle. Turns out that an old Sharps "Big Fifty" (50-90 cartridge, not later 50-140) can not only shoot 1500 yards (and it's within sight adjustment range), but can go 3500 yards.
09 April 2009, 06:19
Roll-Crimpquote:
Originally posted by onefunzr2:
"Bullet velocities were measured with advanced Doppler Radar."
That was the first sign to me that the article was bogus.
Really?
Back in the mid 70's Fairchild (the A-10 guys) did some R&D with mobile radar systems in an attempt to distinguish small arms projectiles by radar signature with microwaves. I believe one of those projects was called SCORE for Spatial Correlation something Radar something else... ?
Too many Fourier Integrals in that line of research to wrap my head around.
So why is doppler, 35 years later such a stretch?
Combined with a heavy foot, Doppler radar is what probably got you your last speeding ticket.
Can Doppler radar accurately track bullet projectile velocity? Absolutely! But don't take my word for it, there is plenty of reference material that is easy to get to.
09 April 2009, 06:55
Tyler KempIt looked pretty legit to me. I wondered why a golfball was more aerodynamic than a marble of the same size...why wouldn't a bullet?
Love shooting precision and long range. Big bores too!
Recent college grad, started a company called MK Machining where I'm developing a bullpup rifle chassis system.
09 April 2009, 07:01
SR4759I think the Phalanx 20MM system uses radar to steer the stream of projectiles onto the target.
09 April 2009, 07:45
Roll-Crimpquote:
Originally posted by Ozzie:
You might want to check the date on the report.
April 1st
If it is true, that this is not true,
then I truly am embarrased! Did I step, read that; took a bigass header on a fools post? Please, say it ain't so.
Sorry
to everyone
that followed me down that path
09 April 2009, 10:10
NEJackGood April Fool's article.
Though, over a few adult beverages, I have wondered if it would work. You would need to be very careful that the dimples didn't change the center of gravity, and probably shoot the thing in a sabot.
09 April 2009, 12:33
Winchester 69Lee Petty once claimed the same virtue for a vinyl top on his car. Turns out the roof metal was too thin after acid dipping. Golf ball technology.
________________________
"Every country has the government it deserves." - Joseph de Maistre
09 April 2009, 16:13
buckoHell Roll Crimp don't sweat it, I have long thought that it would work.
So I was ready to believe as well.
The dopler and the air flow charts set off some red flags for me.
But it makes perfect sense to me and I also remember when Sat night live did a spoof on three bladed razors in their 'because you will believe anything' spot...
(When I was a kid my father used to tell me that God hated a coward, I finally realized he has even less use for a fool.)
09 April 2009, 17:21
onefunzr2quote:
Originally posted by Roll-Crimp:
quote:
Originally posted by onefunzr2:
"Bullet velocities were measured with advanced Doppler Radar."
That was the first sign to me that the article was bogus.
Really?
Back in the mid 70's Fairchild (the A-10 guys) did some R&D with mobile radar systems in an attempt to distinguish small arms projectiles by radar signature with microwaves. I believe one of those projects was called SCORE for Spatial Correlation something Radar something else... ?
Too many Fourier Integrals in that line of research to wrap my head around.
So why is doppler, 35 years later such a stretch?
Combined with a heavy foot, Doppler radar is what probably got you your last speeding ticket.
Can Doppler radar accurately track bullet projectile velocity? Absolutely! But don't take my word for it, there is plenty of reference material that is easy to get to.
The dimples are supposed to give the bullets a better ballistic coefficient. I guess using a simple chronograph to measure the dimpled bullet's greater speed would be to, well, simple???
10 April 2009, 00:24
Roll-CrimpThe dimples are supposed to give the bullets a better ballistic coefficient. I guess using a simple chronograph to measure the dimpled bullet's greater speed would be to, well, simple???
--------------
Dave
NRA Lifemember
member Tonkin Gulf Yacht Club
Yup, simple would be the operative word.
As in "SIMPLETON".
I couldn't spell it, now I are one!
10 April 2009, 00:50
rcamugliaJust saw your thread Roll-Crimp.
Funny as heck! Thanks for the Berger reference! Ha!
The article is great and went in-depth enough to get anyone ...........
10 April 2009, 20:50
tnekkcc
quote:
So, why dimples? Why not use another method to achieve the same affect? The critical Reynolds number, Recr, holds the answer to this question. As you recall, Recr is the Reynolds number at which the flow transitions from a laminar to a turbulent state. For a smooth sphere, Recr is much larger than the average Reynolds number experienced by a golf ball. For a sand roughened golf ball, the reduction in drag at Recr is greater than that of the dimpled golf ball. However, as the Reyn olds number continues to increase, the drag increases. The dimpled ball, on the other hand, has a lower Recr, and the drag is fairly constant for Reynolds numbers greater than Recr.
Therefore, the dimples cause Recr to decrease which implies that the flow becomes turbulent at a lower velocity than on a smooth sphere. This in turn causes the flow to remain attached longer on a dimpled golf ball which implies a reduction in drag. As the speed of the dimpled golf ball is increased, the drag doesn't change much. This is a good property in a sport like golf.
Although round dimples were accepted as the standard, a variety of other shapes were experimented with as well. Among these were squares, rectangles, and hexagons. The hexagons actually result in a lower drag than the round dimples. Perhaps in the future we will see golf balls with hexagonal dimples.
I think I have only had to use Reynold's number once in 30 years of electrical engineering. The mechanical engineers are supposed to do it for me. It shows up when a fan pushes air over a heat sink used to cool a transistor.