A civilian is allowed to buy a guided missile in the US, even importing it from overseas, as long as they have the correct paperwork and their State permits it (many do); building one can definitely be permissible. Most of the restrictions involved in weaponry of this type are related to storage and handling of hazardous materials, in the same way that you generally aren't allowed to store large quantities of high explosives in a suburban garage even though you (until recently) could buy it by the truckload with a driver's license and cash. There is a hobbyist maker culture of DIY weapon designers in the US that has been around for many decades, typically in parts of the US where it is practical to meet safety and legal requirements.

Many people are surprised to discover that as an American you can buy or build almost any weapon system (if you can afford this expensive hobby) as long as you meet basic safety, local legal, and export restriction requirements. For some types of dangerous weapons you may need to file paperwork, but it is more disclosure than permission.

> in the same way that you generally aren't allowed to store large quantities of high explosives in a suburban garage

You can do that with low explosives, you just need a separate, unattached shed, the right license and submit to letting the BATF show up at any time with access to it.

Quite a few of our motor suppliers for the bigger stuff(K/L/M/N) did this, although this was about 5-10 years ago so the laws may have changed since then.

There's basically no high explosives(explodes in open air) used in model rocketry, everything is low explosive(accelerates under pressure), ditto gun reloading and other things that go bang.

> Many people are surprised to discover that as an American you can buy or build almost any weapon system

Citation needed.

At very least in CA, NY, NJ civilian absolutely can not buy/build/posses suppressors for guns, short barrel rifles (SBR), select-fire guns, grenade launchers or any live high explosive devices.

In some states you can build a pipe bomb [2] or buy a grenade having per unit permission from NFA [1]

[1] - https://reddit.com/r/nfa

[2] - https://www.reddit.com/r/NFA/comments/5ffugm/nfa_registered_...

No citation needed, there is no prohibition in Federal law, only State law, and you cherrypicked the most restrictive States in the nation as your exemplars. For example, something like 40+ States permit suppressors. High-explosives was (is? probably with more paperwork now) a retail business in many states; I stopped by one once just to check it out for myself, the only requirement was that I had a vehicle that met road safety requirements for transport e.g. carried on a surface that is not prone to sparking.

I had a couple friends many years ago who, mostly for fun I suspect because they never did anything with it, filled out the relatively simple Federal paperwork that gave them carte blanche to import/manufacture/buy just about any conventional weapon you can think of and they lived in a State with no restrictions. But almost no one does in practice because once you go beyond what is possible to fabricate in a sophisticated machine shop, it would become an extremely expensive hobby for no obvious purpose. Few people can afford to drop millions of dollars on guided missiles.

You won't be doing a ton of damage with these, any structural metal pieces are prohibited and until you start getting into some of the larger high power motors, which are not easy to come by, they don't pack a lot of energy.

Over the years in our club we had a lot of land sharks(pop off the rod and delayed ignition), failure to eject, cato(engine explosion) and various RUDs(rapid unscheduled disassembly). Plenty of cars hit with only minor damage and never any serious injuries.

There’s explicitly no guidance system. It just keeps the rockets more or less vertical. Been following along with his efforts on Twitter for a year and a half or so. He’s made pretty impressive progress and streams a lot of build/debugging sessions and posts a lot of launch videos.

This is at the end of the article.

"The system costs $299, and is only available for sale to residents and citizens of the United States due to ITAR restrictions."