As with the initial report, the key takeaway is that there is no solid body of empirical evidence to support the common gun control wish list items such as bans on modern sporting rifles, magazine size limits, minimum age requirements for purchasing a firearm, universal background checks, licensing and permitting requirements or mandatory sales reporting and registration.
Also, the methodological quality of the existing body of research is low at best. As the report concludes, “the scientific literature we reviewed shows that many of the best recent studies suffer from important methodological limitations that should be addressed in future research,” and, “with a few exceptions, there is a surprisingly limited base of rigorous scientific evidence concerning the effects of many commonly discussed gun policies.” We know this already, of course.