In short, the '94 AW ban prohibited the manufacture (for civilian use) of high capacity magazines (more than 10 rounds, or 5 for shotguns, IIRC) for pistols and rifles.
It also prohibits the manufacture or importation of "assault weapons" for civilian use, but defines an assault weapon by certain specific features which are not essential to the functionality of the rifle but are presumed to be evil by their mere existence.
Specifically, an assault rifle is defined as a semi-automatic rifle that has the ability to accept a detachable, high capacity magazine and
at least two of the following five features:
Pistol grip
Folding or collapsible stock
Bayonet lug
Flash hider
Grenade launcher
You can only have ONE of those features on a post-ban semiautomatic rifle that accepts a detachable magazine.
The ban grandfathered all existing "assault weapons" and high capacity magazines.
When the ban sunsets, this simply will no longer apply.
After the ban sunsets, it WILL be legal to configure a "post-ban" rifle as an "assault weapon" as described in the ban, unless other legislation is enacted that prohibits that from occurring. At this time there is no such legislation pending in Congress.
The Brady Bill concerns only the system of background checks performed when people go to purchase a gun from a licensed firearms deal. That's all it does. It does not have a sunset
clause. (Part of it did, and it has expired. What remains is permanent.)
That's it in a nutshell.
CJ