Yes. US street culture is simply very aggressive. Lots of US guys seem to think being tough and uncompromising is something admirable. When a tough and uncompromising character meets another tough and uncompromising character aggression is often a result. If there are weapons around they will be used and a gun is a very effective weapon. Also if a gun is used in a robbery or a house breaking then logically someone is more likely to be shot and because bullets do a lot of damage they will be more likely to die - as opposed to someone who has been beaten with fists.

Fundamentally your violence problems are cultural. There are countries in Europe with high levels of gun ownership but they do not have the violence on their streets or gun deaths that you have in the US. Guns are not really the problem. BUT, while you still have an aggressive cultural character, having guns freely available does make your society far far more dangerous for everyone.

You need to become less aggressive and take the guns off the criminals. There is your solution. So do you do that by opening another gun shop? Won't these guns actually end up in the hands of the criminals? Every single gun on the streets was originally made and sold legally wasn't it??