As far as I can tell, the 500k-3m figure is from an unpublished[1] report that was commissioned by the CDC - further validation could be helpful. There is also

As far as I can tell, the 500k-3m figure is from an unpublished[1] report that was commissioned by the CDC - further validation could be helpful. There is also separate disputation of the figure in a report[2] by Harvard's Injury Control Research Center. [1] - https://www.washingtonpost.com/news/wonk/wp/2015/01/16/the-study-that-gun-rights-activists-keep-citing-but-completely-misunderstand/ https://www.washingtonpost.com/news/wonk/wp/2015/01/16/the-s... [2] - https://www.hsph.harvard.edu/hicrc/firearms-research/gun-threats-and-self-defense-gun-use-2/ https://www.hsph.harvard.edu/hicrc/firearms-research/gun-thr...