In the final analysis, all gun crimes are a matter of immorality, not a failure of gun laws. More laws do not equal more morality. Even God couldn't pass laws that tell lawbreakers to stop breaking the law. His Ten Commandments are routinely broken. Publishing his laws over a billion times hasn't stopped people from breaking them.
The left is too frightened to start confiscating existing firearms. If they try, it will mean they are willing to revoke the second amendment. Gun confiscation is something they have always wanted, but are afraid to admit. If it's ammunition, more people will learn to reload existing spent casings. When HR8 doesn't work (and it won't) there will be a HR9 and HR10. ... eventually there will be a HR~0~ (confiscation of all existing forearms) That's the end game the left cannot admit, but desperately wants.
I guess the moral of that story is. Neither government nor criminals believe in being moral. For that reason, the Founding Fathers considered the second amendment to be a God given right. ~ Go Figure ~