Parts kits laws

Question
I don't suppose you know the federal laws on parts kits these days?  I'm thinking about going the cheap route and was wondering what the legality on all this was.  As far as I can tell, Missouri doesn't have any state-specific laws concerning parts kits, so it's all the federal law.

Answer
There's not enough information here for me to answer your question.  A parts kit to make what?

It it's a BATF classified "machine gun" then you cannot legally built it last time I checked.

Certain guns (like FALS) have to have certain parts and a certain percentage of the gun made with American-made parts.  Other guns (like AR-15) may not have ANY M-16 parts making up the trigger group, even if the isolated part will not enable full-auto capability.

If it's a rifle, it can't have a barrel length of less than 16" unless you want to get the class III tax stamp for it (I think it's $200)

The reciever is what BATF classifies as the gun, so if you're going to buy one of those it will be like purchasing a firearm.  After that, as long as you observe legal parameters, you should be able to do anything to the gun you want.

I believe that if the gun is private use, and you are not setting up a factory (i.e. there's only one or two), you can make your own receiver without serializing or registering it - this assuming you have the metalurgical and machining skills to do this - it's not something I would recommend.

Lastly, you should check all of this information with a local gun dealer, particualarly one who is a class III dealer will be up on all the latest laws.

You'll probably get further if you tell him specifically what you would like to do (i.e. what gun you want to build).  He'll then be able to tell you if you can do it, any restrictions, and what parts (if any) must be domestic, and which ones can be of foreign manufacture.

Good luck.