Two Democratic lawmakers on Monday will announce new legislation to regulate the online and mail-order sale of ammunition. Sen. Frank Lautenberg (N.J.) and Rep. Carolyn McCarthy (N.Y.) said the new law would make the sale of ammunition “safer for law-abiding Americans who are sick and tired of the ease with which criminals can now anonymously stockpile for mass murder,” in a statement released Saturday. The lawmakers cite the recent movie massacre in Aurora, Colo. for spurring their bill. “The shooter who killed 12 and injured 58 in an Aurora, Colorado movie theater this month had purchased over 6,000 rounds of...