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This is an awesome gun. It is very fun and not that difficult to make. It is also very cheap. The entire thing including a bunch of ammo could easily be made for ~$20, or much less if you already have a lot of the stuff ( you probably do). I spent about $15 but a lot of what I spent it on is extra and can be used on other things. I broke this instructable down into two parts: rockets and launcher, because it involves a lot of steps ( I didn't divide it into two i'bles though, just this one).

-This is in the Krylon contest because it's painted with Krylon.
-This is in the "launch it" contest because it launches rockets.
-This is in the Celestron space challenge because it uses rocket propulsion. And it would work in space I think.

Quote from ATF relating to the legality of this project:

"...As defined in 26 USC subsection 5845(f) (2) the term destructive device includes any type of weapon by whatever name known which will, or which may readily be converted to, expel a projectile by the action of an explosive or other propellent, the barrel or barrels of which have a bore of more than one-half inch in diameter, except a shotgun or shotgun shell... The term 'destructive device' shall not include any device which is neither designed nor redesigned for use as a weapon ; any device, although originally designed for use as a weapon, which is redesigned for use as a signaling, pyrotechnic , line throwing, safety, or similar device; surplus ordnance sold, loaned, or given by the Secretary of the Army pursuant to the provisions of section 4684(2), 4685, or 4686 of title 10 of the USC; or any other device which the Secretary of the Treasury or his delegate finds is not likely to be used as a weapon, or is an antique or is a rifle which the owner intends to use solely for sporting purposes. ..."

This quote is from: http://www.launchpotatoes.com/index.php?act=viewDoc&docId=7

I think that means this is legal as long as it is not used as a weapon.
Well, i must say this is extremely awesome. ive made pump action things, and rocket launching things, but never thought of combining the two. here is what i have to say:<br><br>-amazing design. simple, cheap, lightweight, and requires no special tools. t<br>-looks badass and seems to operate well<br>-the clip fed system is really nice<br>-ignition system is simple, requiring no knowledge of electronics<br>-i would make this, but i would make it larger diameter, and modify it to use store-bought model rocket engines. the home-made rockets are nice, but i have never felt entirely safe with them, just my paranoia. unfortunately, store bought rocket motors are prohibitively expensive.<br><br>AMAZING JOB. keep it up
Thanks! It would be awesome if you made one of these that uses estes motors. Let me know if you do it.
<p>if you want the rocket to not go billisic mke a extension barrel </p>
First of all awesome instructable. Secondly AWESOME ible
<p>Have you thought about making one that shoots mini rockets via burst? That would be cool.</p>
<p>Ya burst and auto, and of course a time fuse so it explosed after a certain distance. You can see some more about how I would like to develop this if you want by looking here: </p><p><a href="http://www.ourbadscience.com/#!rockets--missiles/cmwq" rel="nofollow">http://www.ourbadscience.com/#!rockets--missiles/cmwq</a></p>
<p>Now if you modify the engines to have a firecracker attached to the end of it you'll have bolter rounds :D</p>
That's basically the gist of the legality quote, but the portion where it defines that &quot;the term destructive device includes any type of weapon by whatever name known which will, <em>or which may readily be converted to, expel a projectile by the action of an explosive or other propellent,</em> the barrel or barrels of which have a bore of more than one-half inch in diameter,&quot; could be used in a court to say that this item could be easily and readily made into a weapon which means that it is, essentially, a weapon. Just be very careful about the use of the term &quot;Gun&quot;. Since we commonly associate that with weapons. aside from that, you should be fine provided you make it clear that it is not a weapon nor is it intended to be used as one.
how far do the rockets fly?
I am not sure of the max range, but I have 3 more fuel grains and I've been wanting to shoot this thing again so I might find out since you asked! Maybe on the 4th of July... anyway I'll tell you if I find out.
I love this! I'm currently working on making one myself, though I may be subbing cardboard for bulsawood (I have a lot just sitting around) to maybe add a little more weight and durability.
lsa wood, I would recommend a cheaper stronger heavier wood like fir or pine.
You're damm scary!! lol. I might build it :) by the it's<br> really cool
I can't help but find your project interesting. <br>Do you think this could be done with regular hobby rocket engines? <br><br>Also, a tried, tested and true method of keeping your rockets flying straight over long distances (100s of meters):<br>1) take a drillbit about half the diameter of your nozzle<br>2) make two marks on your engine where the nozzle and propellant material meet<br>3) drill at 45-75 degree angles at both marked points<br><br>This results in the rocket exhaust being used to spin stabilize your rocket, which is usually quite a bit more reliable and predictable than using fins. <br><br>A friend and I had, at one point, built something similar to this; but single fire and relying on hobby rocket engines for ammo. We were able to reliably hit our target, a 2' tree, at approximately 35m, with a smoke bomb tip attached.
Thank you for that idea! That is great, it reminds me of the nozzle configuration for the gyrojet rockets. I will deffinately try that and might add it to the instructable if you are OK with it, crediting your name for that step.
Of course, I don't mind in the slightest. Feel free to paraphrase or whatever to make it easier to understand... I was never good at writing instructions. <br><br>I'd love to see you test it with your rockets as well, it seems like it would be truly impressive putting out multiple spin-stabilized rockets. Especially with a custom &quot;signalling&quot; tip.
I would love a diagram of the gun.
Sure, i'll draw a cross section in MS paint. What step should it go in?
Awesome diagram! Thanks so much!
OK it's there. Under step 7 &quot;the launcher.&quot;
hmmm...if you could make less smokey fuel, then have smokebomb stuff at the end (might need a longer rocket), you have a smoke grenade launcher.... <br> I think this is brilliant! (your instructable, not my idea)
Yeah, maybe you could use a nitrocellulose based fuel.
Have you tested it with mutiple rockets in the magazine? Does the first one ignite all the others?
I have only shot the one out of it that you see in the video because I don't have a very good spot to shoot it unless I go somewhere. The fuel does not light that easily though so it should be fine, especially with that tape over the nozzle. On the first one I tsted in the video ( the one that had too big of a nozzle) a regular fuse wouldn't light it and it took a sparkler.
please do more tests and take more video! I would really love to see how far it can launch and to see it launch multiple rockets!
I will but it may be a couple weeks or more, sorry. Why don't you test it yourself!
Well done. This is dangerous like a monkey with machine gun, but funny. When I was a boy, I did some pyrotechnics. I was the fear of the neighborhood!
Wow, that is both insanely dangerous and really pretty. Congratulations!
Thank you! Danger and beauty what more can you ask for.<br><br>Please vote for this in the &quot;launch it&quot; and Krylon contests if you think it is worthy. It might not show up that I entered until tomorrow though.