99.97%, probably not an exact number, but close, of the guns owned by Americans will never be misused in any way.
There is a common factor in all the recent mass shootings besides access to guns. Until we find out what is driving the shooters and address it the problem will remain.
I blame not the gun, thus the musing on a code, in the event you don’t want them under lock and key by law. Day dreaming out loud is getting risky around here.