He goes over (very clearly) the fact that black plastic furniture, a pistol-grip, and a collapsable stock don't make an "assault rifle" and demonstrates with an AR-15 and a real M4 - the difference in rate-of-fire (something I hear getting confused all the time by antis lately). He also says "Assault rifles have already been banned in 1986" and gives a link to the Hughes act (he states that older machine-guns have been grandfathered and that the new ban doesn't even allow for that).
He then goes over the difference in shooting at two targets with 20rds in a mag and then with two mags - each loaded with 10rds (it's about half a second).
Thanks. I look forward to the day that the Youtube captioning feature does an accurate job transcribing the script. An attempt like "A$$ salt full banded ate six" makes for some amusing reading, but it's not particularly informative.