Would it be legal to build a firearm just for fun or would this be illegal?

Look in the 'build it yourself' section.

In many cases, a citizen can create a quality firearm without violating any laws.  All NFA regs apply...

In addition to the above (all NFA rules apply...), you cannot build what would be a regulated "firearm" under the NFA without ATF approval on their forms, tax paid, etc.

NFA definitions found here: 26 USC 5845

Specifically, make sure your zip gun doesn't fall under the "Any Other Weapon" (AOW) definition in the NFA.

Cheers, Otto

No I am just talking about a simple pistol. Where is the DIY section?

http://www.ar15.com/forums/forum.html?b=3&f=4

http://www.ar15.com/forums/forum.html?b=4&f=51

Quoted: No I am just talking about a simple pistol. Where is the DIY section?

Good to see you over here, but you have to remember that this is an AR15 board, and questions outside of the AR15 realm are not going to always be looked at the same way as other places.  

In your state, a zip gun would get you and your Dad in a lot of trouble.  Building a firearm like a 1911 would not.

Email or PM me if you need to.

I have never built one, I was just curious. I read section 922o and it says "federal law does not restrict a non licensee from making a firearm for personal use and not for resale", It goes on to say that as long as it is for personal use, it requires no serial number! But I am gonna play it safe and not do it at all! Thanks Stickman!

I mean no offence but are you over 21?

If so, and I don't really know that you need to be over 18 but building guns is a lot of fun and quite a challange....  If you build your "zip" gun in a way that it is not an NFA weapon in might be a fun project to try but before you go that route why not try building an AK, AR of FAL?  If you like handguns try to buld a sig, 1919a4 or ???.  It requires some tools and quite a bit of work but you won't have a zip gun when you are done that might just blow up in your face...

Now, most zip guns I have seen pictures of would likely fall into an AOW category or perhaps SBR and these will require taxes and background checks through the ATF and FBI....