The argument is a tautology, it can't be wrong! If guns ownership is a crime, then owning a gun makes you a criminal.

The tautology is compatible with the hypothesis that if guns were confiscated and illegal, eventually there would be a decrease in the amount of people getting shot. Probably an increase for a while as confiscation attempts resulted in agents getting in gun battles with people who don't want to surrender their property.

Whether the loss in life and liberty is worth the outcome is a matter of personal taste.