The folks involved in these activities are often dealing in other banned substances, so it's not obvious that banning actually reduces. "but guns are different

The folks involved in these activities are often dealing in other banned substances, so it's not obvious that banning actually reduces. "but guns are different than drugs". Yes, guns are durable. I don't know how long cocaine lasts, but 100 year-old cartridges are perfectly good. Even if you assume one gun per murder, the required volume is a small fraction of drug smuggling. Oh, and guns are actually easy to make. They're 19th century tech.