"firearms with magazines that hold more than 10 rounds are assault weapons (and therefore should be banned)" seems to be more along the lines of arguments I've actually seen. I probably oversimplified in my head when I wrote the first post. Of course, having a Federal statute that happened to define firearms in that way might have directly led to such arguments after the ban expired, but it's probably appropriate to label some laws as having "The Worst Legal Categorization in the World" as well. What if banning firearms with magazines holding more than 9 rounds would have saved even one extra life?