I was only responding to your direct point about the damage non-gun killings can do. Neither of us can really confirm or deny OB's point because it's a prediction: If you add more barriers to guns, people will resort to other tactics for mass killings. It's slightly corroborated by evidence from other countries where strict gun laws are coupled to greater violence of other forms, but it's still basically impossible to confirm or deny without making changes to the law. Rather it's something to keep in mind when trying to design a way forward. And for the record, I'm fine with background checks, but I think most gun legislation presented post-shootings is reactionary, poorly thought out, and usually ineffective. (See: magazine capacity limits)
I don't disagree that a non-gun killing can be similarly or more deadly compared to a gun killing. The point I take issue with is that they can be interchanged such that a person who would commit a gun killing would instead commit a non-gun killing with similar effectiveness. I also agree when comparing US deaths to deaths in, say, England, it's inappropriate to suggest the sole difference is access to firearms. It is certainly a variable that can't be ignored, but it's one of many variables. I'm cynical to the point of assuming any legislation, whether reactionary, related to firearms, or something else entirely, is poorly thought out and ineffective. My point, which may have been poorly stated throughout this thread, is that we could do better than we are doing. I don't have good suggestions for how to get there, unfortunately, and with politics and culture the way they are, doing better may be impossible.