SpudFiles

Lol. I'm not gonna say anything...much You should really measure your distances before claiming stuff. And that bouncy ball would have to be made of lead to get it a half mile, and you would need ridiculous amounts of pressure.

quick question.. sortof off topic but not really...

What is the Cd of a smooth sphere... I've seen everything from .1 to .5 listed as the Cd, depending on the source, typically scientific sites list lower #'s, and hobby/enthusiest sites list higher #'s...

jeepkahn wrote:What is the Cd of a smooth sphere... I've seen everything from .1 to .5 listed as the Cd, depending on the source.

It does actually vary somewhat depending on exactly how smooth the surface is.

I personally use about 0.45 for most spheres. I'll use 0.5 if it's a notably less smooth surface, and things like chromed steel ball bearings may warrant less (0.35-0.4) because they're somewhat smoother.
The design of golf balls places them at around 0.3. Anyway, for our purposes, sphere-like shapes don't ever go below about 0.3

Of course, the question remains of "At what velocity?". The Cd of a sphere is 60% higher at Mach 1 than it is at Mach 0.5
It's reasonably constant below Mach 0.5, but above that, it rises sharply, with a near linear increase between Mach 0.6 and Mach 1.2
It then rises slowly to a peak at Mach 1.6, then slowly decreases again - but at supersonic velocities, the Cd is always worse than at any subsonic velocities.

Anyway, this long yet steep rise between Mach 0.6 and 1.2, with a peak as late as Mach 1.6 is an illustration of the fact that spheres have a very large transonic range.

There is the rifle, With its 1/2'' barrel, and an old valve. new one is being worked on.
The half inch barrel is the one ive been talking about reaching the 1/2 mile range. I repeatedly stated that it shoots bouncy balls, and the it gets 1/2 mile ranges.... please let me clarify.

It does shoot bouncy balls, and it DOES get 1/2 miles ranges.

But, not at the same time. The ranges are only with .50'' balls. not bouncy balls.
I will post this rifle in its own topic shortly. right after i take a few videos for y'all.

your saying you get 1/2mile with a sprikler! you must be mad!

so what sort of pressure are you using in that 1/2" pvc to obtain a half mile .
my first pnematic used a 1" sprinkler my barrel was longer and my chamber was 10x bigger than urs, and i predicted that it would shoot a marble 300m max, with thoses specs in comparison to urs i dont think a half mile is possible...

Mate he has stated repeatedly that the 1/2 mile range was not with bouncy ball's, it was with a lead one or something.

jmadden91 wrote:Mate he has stated repeatedly that the 1/2 mile range was not with bouncy ball's, it was with a lead one or something.

lmao sorry dude but you should of quoted me,now you look like the fool

i got messed up with the fact that it has the capability to shoot a half mile,and it also has the capability to shoot bouncy balls, but not both at the same time

I can attach a 1'' barrel, to shoot bouncy balls. Or a 1/2'' in one for steel/lead balls.
Obviously, the 1/2'' one gets better ranges, so far those ranges have been right around (slightly higher than) 1/2 mile.

im still waiting for this proof. if it is true then you would be the god of spudguns to get 1/2mile out of a sprinkler. if not then you will be just anougher dude exagerating on distance......

And make sure when you make the video your fiancee shoots the gun it makes this thread a hole lot more interesting..

If you give in now, you won't be as embarrassed in the future when you realize you are wrong.

Sorry but if you haven't realized yet, 1/2 mile claims are frowned upon unless you've got a great rep and more importantly, a cannon capable of the job. I look forward to your proof and will truly be shocked if your claims are true.

Today I shot a dinosaur egg encased in ice from a glacier 65 million years old collected from glacier national park in montanna. The shot was 2750 feet from launch to landing, or a little over 1/2 miles out of 10 gallon. (oh yea, the egg was fletched)

I too am a bit perplexed by the OP's claims, it's almost as if he's trying to fool us by wasting our times arguing against such a claim nahhhh, he wouldn't do that...

I assume that's a sprinkler valve. Doesn't matter anyway, could be a 4" piston valve for all I care, that cannon in the picture couldn't shoot half a mile.

What pressures do you use it at? With such small bore PVC you probably could be pumping that up to 300PSI, makes little difference anyway, still wouldn't shoot the half mile.

I can believe the 10 gallon story, but not this one. I built a SV cannon with a 8-9' .75" barrel, and a 3' 2" chamber. That shot a AA battery about 1/8 of a mile to 1/4 of a mile at 140 PSI. That one was a whole lot bigger than yours, and shot half the "distance" you claim.