Bad guys and felons will get guns regardless of what the laws are.
Check this out:

Gun advocates asked the U.S. Supreme Court on Monday to overturn a lower court’s ruling against state laws designed to buck federal gun rules.

Earlier this year, the 9th U.S. Circuit Court of Appeals upheld a district judge’s decision against the 2009 Montana Firearms Freedom Act. The law attempts to declare that federal firearms regulations don’t apply to guns kept in the state where they were manufactured.

Other pro-gun states have passed similar measures.

The Justice Department has argued successfully that the courts already have decided Congress can use its power to regulate interstate commerce. Some gun-control advocates sided with the federal argument, saying “firearm freedom acts” would allow felons to obtain guns without background checks and make it harder to trace guns used in crimes.