Law Enforcement Officers Protection Act of 1985

prohibits the manufacturing, importing and selling of ammunition that can penetrate a bulletproof vest

Law Enforcement Officers Safety Act (LEOSA)

 outlaw the manufacture, import, or sale of armor-piercing ammunition except for government use, including military and police, testing, research, or export

http://www.ncjrs.gov/App/publications/abstract.aspx?ID=153209