Is 1/4" ballistic steel 550BHN really level III+ rated?

[AR500 Armor]

Is 1/4" ballistic steel 550BHN really level III+ rated? We put it to the test against 5.56 rounds traveling around 3,000 feet per second.

What is level III+ Body Armor? http://www.ar500armor.com/what-is-le...ody-armor.html

Remember - not all body armor is created equal, and not all manufacturers test methods are the same and state accurate velocity limitations. Regardless where you choose to take your business, we hope this information helps educate you on making an informed decision when it comes to purchasing body armor.