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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.
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.
you got my vote
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.