It's not that hard; SailorCurt works their new "study" over with some simple math. Check it out and be educated.
I tried to read their latest piece about "assault weapons," but got fed up on about the 7th or 8th page when they erroneously assert that pistol grips, barrel shrouds, and the like make weapons more dangerous. They believe that it makes "hip firing" easier, despite the fact that armies don't hip fire because you can't hit anything that way. You must realise that they are activists, and not experts on anything firearm related.