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Posted: Mon Jan 05, 2009 10:33 pm
by salasd
the best shape i know of is called the sears hackbody, which looks like a cigar with pointed tips on each end. its best for areas around the super sonic speeds but i think its should be ok. somthing simpler though, golfballs

Posted: Tue Jan 06, 2009 12:54 am
by Lentamentalisk
Salasd, the closer observer would notice that golf balls have already been mentioned exactly 15 times in this article already (not counting quotes.) Before you post an obvious answer, check to make sure that answer hasn't been posted 15 times...

Posted: Fri Jan 21, 2011 2:44 pm
by jackssmirkingrevenge
Interesting footnote to this from the wikipedia article on nosecones that Rag had linked to, an excel calculator that will design one for you, meant for model rocketeers but certainly applicable to spudgun projectiles for those seriously interested in long range.

Posted: Fri Jan 21, 2011 3:42 pm
by Labtecpower
I looked back one page, and I saw rag talking about ice bullets.
(JFK kill theory)
What if they made a bullet out of bone, or frozen meat / gelatine / other body tissue? I think they would have better mechanical strength than just plain water, and aren't tracable.

Wat do you guys think about this?

Posted: Fri Jan 21, 2011 4:40 pm
by Hotwired
Labtecpower wrote:I looked back one page, and I saw rag talking about ice bullets.
(JFK kill theory)
What if they made a bullet out of bone, or frozen meat / gelatine / other body tissue? I think they would have better mechanical strength than just plain water, and aren't tracable.

Wat do you guys think about this?
Firing bone or dead meat hasn't got much going for it aside from being rather grisly.

The untraceable bit of an ice bullet is that it melts and thus leaves no evidence. The practical side of making and firing one is another matter.

If you're going for something with mechanical strength you might as well go the whole hog and use metal, either way forensics have something to examine.

Posted: Fri Jan 21, 2011 5:10 pm
by ramses
Now that this has been kicked up, I have to mention that no-one has talked about skin drag. Torpedoes achieve low(er) drag with cavitation. As long as the fins are out of the cavity, this shouldn't hurt stability.

Posted: Fri Jan 21, 2011 5:44 pm
by ilovefire
Labtecpower wrote:I looked back one page, and I saw rag talking about ice bullets.
(JFK kill theory)
What if they made a bullet out of bone, or frozen meat / gelatine / other body tissue? I think they would have better mechanical strength than just plain water, and aren't tracable.

Wat do you guys think about this?
been tested by the myth busters with both frozen meat and ice, if i remember correctly the ice just turned to steam and the meat was more of a mince shotgun, both non lethal, altho they did only use firearms dont know how they would have gone in a air gun

Posted: Sat Jan 22, 2011 12:58 am
by jackssmirkingrevenge
ramses wrote:Now that this has been kicked up, I have to mention that no-one has talked about skin drag. Torpedoes achieve low(er) drag with cavitation. As long as the fins are out of the cavity, this shouldn't hurt stability.
wikipedia wrote:Supercavitation is the use of cavitation effects to create a large bubble of gas inside a liquid.
... so not really relevant to spudguns unless you've made a speargun ;) unless it's possible to create a vacuum bubble - but surely, if there were a simple way to do this, we would have seen in on military projectiles already?

Still, bloody hell!

[youtube][/youtube]

On the subject though, one other drag-reducing concept not mentioned in this thread is the "base bleed" idea, though really if you're going to do that, might as well make a rocket assisted projecile.
(JFK kill theory)
Very interesting documentary including a detailled ballistic test showing the "single bullet theory" to be feasible, and talk of ice bullets to be a little silly ;)

[GVideo]http://video.google.com/videoplay?docid ... 2571189886#[/GVideo]

Posted: Sat Jan 22, 2011 1:05 am
by POLAND_SPUD
"base bleed" idea, though really if you're going to do that, might as well make a rocket assisted projecile.
that sounds feasible... well sort of
if you really want the max range possible you might turn the projectile into a steam rocket

Posted: Sat Jan 22, 2011 11:15 am
by ramses
Somewhere I read that you can also get air to cavitation. Perhaps I was mistaken.

Posted: Sat Jan 22, 2011 11:31 am
by Technician1002
You can. That is the cause of sonic booms. Supersonic flights result in areas in vacuum.

Posted: Sat Jan 22, 2011 6:43 pm
by saefroch
Technician1002 wrote:Supersonic flights result in areas in vacuum.
I assume you're talking about the rarefaction that travels behind the buildup of sound waves that occurs around the object. Certainly an interesting proposal, but to make significant use of that I'd think you need a significant sound source, which most aerodynamic projectiles do not create.

But still, isn't it possible to create a region of far lesser pressure with a specifically designed projectile?