Quick examples: Minneapolis, Boston, Nashville, and Cincinnati all have much higher percentages of non-Hispanic whites than Los Angeles and New York.
Even if we look at black or Hispanic/Latino percentages:
* Minneapolis: 18.6% black, 10.5% Hispanic/Latino
* New York: 25.1% black, 27.5% Hispanic/Latino
* Los Angeles: 9.6% black, 48.5% Hispanic/Latino
I wouldn't go so far as to say that the data is "all over the place," but I would definitely not say there's a correlation with race.
Non-Hispanic blacks (2.8 per 1,000) and Hispanics (2.2 per 1,000) had higher rates of nonfatal firearm violence than non-Hispanic whites (1.4 per 1,000) https://www.bjs.gov/content/pub/press/fv9311pr.cfm
http://kff.org/other/state-indicator/firearms-death-rate-by-...