The 2nd Amendment grants citizens the right to bear arms. Some have relinquished those rights due to past crimes. The Brady Law requires background checks prior to purchasing a gun from a registered dealer to prevent convicted felons and mentally disturbed from having easy access to weapons.
Close the loop holes to require a background check on all purchases; no exceptions. Convict those that fraudulantly skirt the law (straw sale) and give weapons to those that would not have passed the background check.
Require a beckground check on file for ammunition purchases.
Stop making it easy for criminals and the those that are disturbed from mass killings.