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Super Slick Ammo (Literally)

Post about things you have launched or thought about launching. Also post about various materials used for building cannons. No posts about explosive projectiles!
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Unread postAuthor: ALIHISGREAT » Tue Oct 30, 2007 12:43 pm

i do metric but imperial is not that hard to understand and its not that hard to roughly convert.
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Unread postAuthor: jimmy101 » Tue Oct 30, 2007 1:36 pm

jimmy101 wrote:I agree with Necrosis.

Fiddle around with GGDT, you'll find that friction has a pretty minor affect on the performance of a compressed air gun.

yes but it still affects the performance... and better performance is well... better.

That is kind of a simplistic view.

A gun shoots a $0.10 round at 400 FPS. Swtiching to a $1.00 low friction round (of the same mass and shape) increases the velocity to 410 FPS. Is it worth it?

Most spud guns are not all that consistent shot to shot. A 5% shot to shot variability is not uncommon. In order to measure the difference between 400FPS and 410FPS (a 2.5% difference) you would have to shoot the gun many times. A Student's T-test would be need to tell if the observed difference is real or just a result of random variation.

It is entireley possible that a low friction round would increase the muzzle velocity so little that the increase is unmeasurable. Indeed, that is about what GGDT predicts would happen.
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Unread postAuthor: ammosmoke » Wed Oct 31, 2007 2:03 pm

hubb017 wrote:
ammosmoke wrote:Augh...So, I have to fricken convert it...

You could always learn both. :D

I know how to work the metric system, ie, 100mm=1 cm, 100cm=1 meter, 1000m= a kilometer...etc, but when I try to picture it in my head it just doesn't work. I see things in inches and feet. If somebody says "its 20 meters away" I go, hmmm, well thats over 60 feet, ok, now I understand how far away it is. Same pretty much goes with yards, because we don't use them very much. If somebody says 30mm gun, I think, hmmm, now a 9mm is this big, so how big is 30 again? Barrel length, 50mm, umm, how much is that in inches? I know cm-inches 3.54, but still, I like to be able to picture in my head how far it is without converting. That is why I wish everyone had one measurement to start out with.
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