While I was waiting, I did the same with 2010 data... link is
https://docs.google.com/file/d/0B0XD...it?usp=sharing
One PDF is the basic form. The other two, I pulled out the Permissive vs Restrictive totals, and sorted the whole sheet on firearms homicide rate.
The "bad" half (25 of 51) had 10 of the 18 restrictive jurisdictions. 6 of the top 10 on the bad half were permissive. Flipped and sorted the other way, 11 of the top 12 were permissive. None had extremely high populations. I'll be adding a population density column in the near future though. I eyeballed the page on the Census website with pop density, and just eyeballing, my gut says it'll be suggestive but not definitive.
Stronger correlations are geographical- states that were Confederate, or border states with Confederate leanings litter the top of the "Bad" list. States so far west they weren't even a state in 1860 dominate the "good" list.