Looks to me like the Dems didn't get the public outcry for a gun ban that they expected from the Las Vegas event. The Dems already had an Assault weapons ban written up, they were just waiting for the "event" to happen.  That didn't work, so the Dems had to do Parkland instead and rename the legislation that they had written up before hand in 2017. https://www.congress.gov/bill/115th-congress/house-bill/5087/text See the title to Appendix A:   APPENDIX A—FIREARMS EXEMPTED BY THE ASSAULT WEAPONS BAN OF 2017 Centerfire Rifles—autoloaders