A little project I would like to do.

[3VIL G3NIUS]

Do you realize that I was only making an example? Enough flaming, its just a point. I know I can't propel a airsoft bb 500m, and it would need a huge cannon to do it, plus an amount of money that I don't have. But I am still going to try this, its not going to be some 3inch chamber to a 1/4" barrel... Its going to be a 3/4" or 1/2" chamber to a 1/4" or 1/8" barrel...

Just stop commenting on the thread if you aren't going to be any help...

Oh and Evil, its my mom. She would kill me if she found out. Read posts much?

Yeah I do actually.
I asked why she would kill you? Does she not like flammable things or something? Or just anything that shoots?

Anyway, I'd make the chamber like 1.5" and however long it should need to be to fit into whatever you use as the stock of the gun.
A cartridge system would be the best though, as it would be possible to reload it quickly.

[ramses]

Honestly, a 1.5" diameter chamber seems like overkill. a 1x2" chamber would give you a C/B ratio of over 1.5:1 with a 20", 6mm barrel

(go hybrid)

[warhead052]

Evil, she hates guns, and if she knew it was a combustion before it was even built, well I wouldn't be on the forum anymore.

Ramses, overkill is ok, I need power to reach longer distances anyways...

[inonickname]

Do you realize that I was only making an example? Enough flaming, its just a point. I know I can't propel a airsoft bb 500m, and it would need a huge cannon to do it, plus an amount of money that I don't have.

A barrel 499m long would do it

When you say "huge cannon", I don't think you understand exactly what is meant. On launch that airsoft BB would have more than 3 times the muzzle energy of a 155mm howitzer.



Just letting you know DYI was being facetious. You'll have done something pretty special if you can get plastic to those kinds of speeds.

[warhead052]

Yeah, well I bought a sparker, and it works. I just need to install my tighter barrel and its done. It sounds awesome, I use lighter butane for now, I am going to try something like axe or something later. Right now it just goes whomp and launches a bb about 10 feet, with my 1/4" pex tube (bbs fit but do not slide out, you gotta apply pressure for them to move), they should go a bit further..

[saefroch]

Your mix is off if it's not making a clear, sharp sound. Also, if the material is any kind of transparent, shooting at night is amazing to behold.

Get a meter of some sort. It should be shooting a BB much farther than 10 feet.

[jackssmirkingrevenge]

Consider a .22lr, it's not very accurate beyond 150 meters. That's using a precision rifled barrel shot by a skilled marksman with quite a bit of practice.

[youtube][/youtube]

Good enough to be a sniper round according to those nutty Russians

I haven't simulated this (nor will I) with gravity included, but that level of performance would, with the heaviest available airsoft rounds (0.43g), require a muzzle velocity in the neighbourhood of 250km/s (give or take about a hundred kilometres per second, because I've got better things to do...)

According to GGDT's external ballistics calculator, even fired at over 1.6km/s at an indirect angle it won't go past 200 metres.

[warhead052]

Jack, 200m is fine. I don't need/have the space for it anyways. What fuel ratio? Oh and I use butane from a lighter (I just hold the thing down to let gas in) and then hit the sparker, and I gotta blow into the chamber to make it fire. Is that normal?

Sae, it only shot that far with a 3/8" barrel. I added my 1/4" barrel which is the equiv of a tightbore airsoft barrel and it shoots at about 75-100 feet. I hit a neighbors shed which was about 200 feet away some how though. I gotta figure out a way to add a hop up because this thing curves any which way it wants...

[Lockednloaded]

Jack, 200m is fine. I don't need/have the space for it anyways. What fuel ratio? Oh and I use butane from a lighter (I just hold the thing down to let gas in) and then hit the sparker, and I gotta blow into the chamber to make it fire. Is that normal?

Sae, it only shot that far with a 3/8" barrel. I added my 1/4" barrel which is the equiv of a tightbore airsoft barrel and it shoots at about 75-100 feet. I hit a neighbors shed which was about 200 feet away some how though. I gotta figure out a way to add a hop up because this thing curves any which way it wants...

You realize how fast 1.6km/s is right? It's not a number achievable b any standard means, much less a combustion

Also, a 1/4" barrel is hardly tight bore for a 6mm BB. for any decent range, get a barrel closer to 6mm

[Gun Freak]

1/4" is 6.35mm, tightbore is 6.03 or less

[warhead052]

1/4" pex is tight enough to where my bb won't roll out no matter how hard I try without blowing into it. And yes, I just realized he said kilometers, I thought it was m/s....

[Zeus]

Remember, 1/8 1/4 3/8 1/2 and up are all nominal sizes, it bears no relevance to the actual pipe size.

Might as well call them micro, mini, normal, large and f***ing huge. Doesn't mean anything really.

JSR, those crazy russians use them under 150m, the main merit is how easily it's silenced.

And Warhead, I really recommend you spend some time playing with HGDT so you grasp what kind of power combustions have. If you don't understand anything in HGDT, please PM me. Once you see the capabilities of combustions then you'll be able to build something quite good.

Take your time though.

[warhead052]

Zeus, I don't really mind. 1/4" PEX tubing is a perfect fit for an airsoft bb, but if you use it in a vortex bbmg, MAKE SURE THEY ARE SEAM LESS! I made that mistake yesterday and it blew the barrel right off because a seamed cheapo bb jammed the barrel...


I need some ideas for fuel, since I exhausted all of our 50ish lighters shootings bb's off in the back yard. I figured out the fps comparing it to my friends m4a1 aeg, this has about 500 fps with the right mixture. I shot at my metal shed, and I heard the pop of the ignition, then a split second later the pop of the bb hitting the shed.

If any of you can help me with syringe metering, or any kind of metering that won't get me into trouble with my mom, then that would be awesome.

[Crna Legija]

Zeus, I don't really mind. 1/4" PEX tubing is a perfect fit for an airsoft bb, but if you use it in a vortex bbmg, MAKE SURE THEY ARE SEAM LESS! I made that mistake yesterday and it blew the barrel right off because a seamed cheapo bb jammed the barrel...

I need some ideas for fuel

propane?

I

figured out the fps comparing it to my friends m4a1 aeg, this has about 500 fps with the right mixture

not sure of the size of your cannon but i doubt that you getting 500fps

If any of you can help me with syringe metering, or any kind of metering that won't get me into trouble with my mom, then that would be awesome.

just measure 4.2 %(for propane) of your chamber volume and put that much propane in you gun.

[warhead052]

Ok, well crna, it launches the bb so fast I cant see it till it hits the target. Its a 3/4"x6" chamber, so I suppose it lets in enough gas to send it flying fast enough. I have to sleeve the 1/4" in 3/8" to straighten it out more, but when thats done then I will try butane metering, the propane. But first I want to try gasoline vapors just to see what happens...