Why not require every gun to have a trigger lock? A lock with only one unduplicable key. If you are caught in public without the trigger lock, five years in jail. If you are caught in public with a key or a gun not registered to you, five years in jail. If the jails become too crowded, release nonviolent drug offenders.
Require that only authorized gun dealers can buy more than one of any particular type or brand of gun. Stop Internet sales of guns; if you want a gun, take the time to do the background check. If you feel that you need 20 9 mm Glocks to protect yourself from a runaway government, find some friends and form a group dedicated to your crazy ideas, but, please, I'm begging you, leave the rest of us alone.