That's not gun culture per se, but gang culture. Gun "culture" in the US is something that trends far more right wing in general, and tends to be mostly white, mostly (nominally) christian.

I can't speak to other cities, but the south side and west side of Chicago (esp. around Garfield Park, Douglas Park, and all of Austin) have a serious gang problem. If you aren't willing and able to engage in violence at the slightest perceived provocation, then you tend to be victimized. The net result is that someone that jumps a line can end up getting a beat down, or killed. (And, BTW, the gang problem is a result of a century of institutionalized racism, combined with a few decades when CPD was exceptionally effective at jailing gang leaders; instead of just two or three major gangs in Chicago, you have hundreds of small ones, all constantly fighting over tiny patches of turf.)