The following states have some sort of Assault Weapons Ban that affects how you can construct an AR-15. In the other states you should be good to go.
CA, CT, DC, MA, NJ, NY, and Cook county (Chicago) IL.
Contrary to popular opinion, you
can have an AR-15 in California. There are three ways.
1) If you owned it before a certain long-ago date and registered it, you can configure it however you like. Catch is there are no new registrations being taken so if you don't already have it, you can't have it now.
2) You can have a rifle that *looks* exactly like a free state rifle. This is called a fixed-magazine rifle. You can have any of the evil features, but you're limited to 10 rounds (and many use a 30-round mag internally blocked to 10 rounds), and the magazine release has to have a lock on it so that your finger can't depress the mag release. Instead you use a pointy tool like the tip of a bullet.
3) You can have a rifle that *functions* just like a free state rifle (30 round mags OK, detachable by a finger press -OK). The only catch is that you have to remove all evil features including the pistol grip. This results in a weapon that has a different appearance from what you're used to, for example this rifle with the Exile Machine Hammerhead rifle stock adapter:
Also contrary to popular belief, it's not illegal to own and use 30 round magazines in CA,
no matter how you acquired them.
-Mark
CEO, Exile Machine LLC