Well, there's no way to define a mechanical difference, which was rather my point, and no need to ban either.
And show me how the NRA caused the former Assault Weapons Ban to not be renewed -- name a single event or action other than simply making public statements that its renewal was a bad idea. You can't. The simple fact is, at the time of the sunset, the people who wanted it renewed didn't have the votes in Congress to get it renewed. About the most fun in this was the at-the-time blaming of it on the president (George W. Bush) who couldn't have extended it if he'd wanted to do so. Now yoiu're blaming the NRA, and it couldn't have extended it if every member had wanted it extended -- again the votes simply weren't there after the Gingrich takeover of the House in 1994.