You could indeed argue that. I think that just enforced the argument that the means do not have a moral aspect, and it is the instances where they are used that causes the goodness or badness of the event. How they are used comes from decisions.

You could also steal something and your life might be better for having a thing, possibly more so than how much worse it makes for the person you took it from.

The thing that distinguishes theft from taxation is a societal convention. Adding consensus around how, what, and why things are taken makes it more consentual. Individuals may disagree with having to pay tax, but as a society it is generally agreed upon (even if the methods of agreeing a flawed)

Things need to be an extreme case for guns to come into that process. It implicitly means the goal of reaching consensus has failed and one group is enforcing their will upon the other. That's usually not a good path for the disadvantaged because the powerful by definition have more capacity to enforce their will. Reaching consensus, whilst slower, is the one that supports the disadvantaged better.