I don't know where you got your gun injuries / death stats, but there are two things to be careful of here:
1) substitution effects. As a hypothetical example, we could have one city that has 30 gun murders per 100k and another that has 130 per 100k, but both have the same murder rate (because you can murder with things other than guns). IMHO the important rate is the murder rate, and how much of it is with guns vs. other stuff is an aside.
2) Make sure your numbers don't include suicides. If they include suicides, they're not informative.
1) substitution effects. As a hypothetical example, we could have one city that has 30 gun murders per 100k and another that has 130 per 100k, but both have the same murder rate (because you can murder with things other than guns). IMHO the important rate is the murder rate, and how much of it is with guns vs. other stuff is an aside.
2) Make sure your numbers don't include suicides. If they include suicides, they're not informative.