SpudFiles

hey how far dose all guys guns shoot
i have a 2inch to a 4inch cumbustion cannon that will shoot about 1/2mile
the chamber is about 3feet and has one fan in it and i use propain
and barrel is about 7 feet long and i just use a lanter sparker
alitte to unsafe but it works the best
wanting to build a 6ich camber that is 4 feet long with three fans in it with a 15 foot barrel and see if i can brake the speed of sound
or get close to it any one got any good iders on that
thanks
coloradoman

Ah first poll on my forums!
I voted
And I added another option.

Have you been able to measure the distance your cannon shoots?

i have come pretty close to messering it well it was more like i shoot about ten pounds of spuds in the sme feild walked way out there till i started finding them and the counted how meny passes it took to walk back from the ferest one i found and then took off about 100 steps because my passes are about 33 feet but there is always alitte bit off and better to be under then over and i fregot exsatly how meny yrds i walked but it was 1/2mile at lest or over sad thing i have goten buisy with work and the cannon has kind of died thinking of just leting the thinhg to in the musem of all the stuff that are to unsafe to use any more and build a new one just this new one i am talkin about is going to cost a few nice pretty pennies

how do i vote?? im sure its simple and im jsut being stupid but i still dont know how

For some reason the poll was set to end after 30 days, I changed it, you should be able to vote now.

I'd say my spud shoots like a half a mile. It's hard to get 'em to shoot much farther, without having a huge chamber, cus there isn't enough room for expansion in a small chamber. But I've figured out that small packages can be big combustion sources. It's cool, how it works!

ya it is funny how those things work see me i go for the big stuff small stuff just dont work to well i got some 6" pipe out side waiting to have a barrel fited and a stand made for it i am hopeing to turn it into long rang altilery you know with a back end long so no have to have a long long pole or some thing to ram what ever you are shooting out you know needs alittle bit of thought put into it yet but i am sure that it will work i hope plan on haveing a lanter lighter as a triger and two fans put into it with three diffrent spots for the porpain injetion going to have to dumble up the pipe and the barrle for stragth but its going to be good much much biger then the one i have now
R.N.D.

bloody imperial measurement, anyhow 1/2 mile is a long way

my first combustion shoots about 250 yards

using aquanet got me my best shot but i think i got lucky but rightguard was way more consistant

I have three combustion guns ,I usually shoot at a tree-line that is about 500' away, they sometimes slam into the treeline with a pretty good smack ,but I don't really think they could go but about 600' most of the time and I have some pretty darn good cannons I think.(maybe they are not very good) I'm only estimating as I have never got out the tape measure or walked it out but it seems that my best pneumatic would only shoot about 7 to 9 hundred ft.with it's 2" barrel. With some of the shots I make the spuds sometime fragment into pieces from the force put on them .

No offense , but I often doubt the people that say they shoot half a mile or 500yds with a combustion thats neither a huge pneumatic or a hybrid. Unless you have Actually measured it, not by walking then sure I would believe you but estimates are often WAY off. [/rant]

Heck, walking would be within a factor of 50% - I'm suspecting the 1,000 yard folks are simply saying "It was going really fast, and then I lost track of it"...

...acctualy, I went to the trouble of finding the range for variusly powered launchers firing varying-massed projectiles with varying Cds. Here it is, distances in feet (a 50" barrel 2" in diameter using a light gas through a perfectly flowing burst disk was used, to keep the energy of launch porportional to the pressure, and unchanging with mass)
The Cd of a potato is assumed to be around .5

<table>
<tr><td><b>Cd</b></td> <td>20</td> <td>50</td> <td>100</td> <td></td></tr>
<tr><td>.1</td> <td>1743</td> <td>2342</td> <td>2780</td> <td></td> </tr>
<tr><td>.2</td> <td>1104</td> <td>1405</td> <td>1622</td> <td></td> </tr>
<tr><td>.35</td> <td>738</td> <td>909</td> <td>1030</td> <td></td> </tr>
<tr><td>.5</td> <td>564</td> <td>618</td> <td>764</td> <td></td> </tr>
<tr><td>1</td> <td>326</td> <td>382</td> <td>420</td> <td></td> </tr>
<tr><td><b>100 g</b></td> <td></td> <td></td> <td></td> <td></td></tr>
<tr><td><b>Cd</b></td> <td>20</td> <td>50</td> <td>100</td> <td><b><pressure</b></td></tr>
<tr><td>.1</td> <td>1807</td> <td>2873</td> <td>3752</td> <td></td></tr>
<tr><td>.2</td> <td>1306</td> <td>1892</td> <td>2346</td> <td></td></tr>
<tr><td>.35</td> <td>950</td> <td>1297</td> <td>1557</td> <td></td></tr>
<tr><td>.5</td> <td>759</td> <td>1004</td> <td>1186</td> <td></td></tr>
<tr><td>1</td> <td>472</td> <td>594</td> <td>682</td> <td></td></tr>
<tr><td></td> <td></td> <td></td> <td></td> <td></td></tr>
<tr><td><b>150 g</b></td> <td></td> <td></td> <td></td> <td></td></tr>
<tr><td><b>Cd</b></td> <td>20</td> <td>50</td> <td>100</td> <td><b><pressure</b></td></tr>
<tr><td>.1</td> <td>1594</td> <td>2880</td> <td>4077</td> <td></td></tr>
<tr><td>.2</td> <td>1269</td> <td>2057</td> <td>2716</td> <td></td></tr>
<tr><td>.35</td> <td>992</td> <td>1486</td> <td>1875</td> <td></td></tr>
<tr><td>.5</td> <td>825</td> <td>1183</td> <td>1458</td> <td></td></tr>
<tr><td>1</td> <td>547</td> <td>731</td> <td>868</td> <td></td></tr>
<tr><td></td> <td></td> <td></td> <td></td> <td></td></tr>
<tr><td><b>200 g</b></td> <td></td> <td></td> <td></td> <td></td></tr>
<tr><td><b>Cd</b></td> <td>20</td> <td>50</td> <td>100</td> <td><b><pressure</b></td></tr>
<tr><td>.1</td> <td>1361</td> <td>2689</td> <td>4078</td><td></td> </tr>
<tr><td>.2</td> <td>1157</td> <td>2055</td> <td>2877</td><td></td> </tr>
<tr><td>.35</td> <td>957</td> <td>1558</td> <td>2063</td> <td></td> </tr>
<tr><td>.5</td> <td>824</td> <td>1273</td> <td>1635</td> <td></td> </tr>
<tr><td>1</td> <td>579</td> <td>820</td> <td>1005</td> <td></td> </tr>
</table>

Now, note:
"The range increase/launcher power increase" is a diminishing return... it get progressivly harder to send your projectile farther.
There are significant differences in range acheivable mearly by using a projectile of a different mass.

It has been a couple of months since I answered this posting. since then I have built cannons using info from burnt Latke to get a correct cb ratio and I have even added stun gun ignition to one of my cannons.. I also use other tricks like cups for burst discs and injecting more air. And guess what , I get around 800' sometimes a little more. My huge air cannon which was 11'6" with a two inch valve will probably get 1000' at a risky 135psi. I dismantled it to build something else because it's just too big to move around.I may turn it into a under over type with a 2" sprinkler valve.