The anti-gun Brady Campaign has been sounding the alarm about the Fabrique Nationale 'Five N Seven' handgun. They claim that the gun easily defeats police body armor and have been calling it an "assault weapon" that should be banned by Congress. (Because only Congressional bans will prevent crime.) They even claim to have a video showing it defeating body armor.

But then there is the Federal Bureau of Alcohol, Tobacco, and Firearms, another anti-gun organization, who is saying something different. (emphasis in original)

In response to numerous questions that ATF has received regarding the capabilities of the 5.7 X 28mm cartridge, the following technical information is provided.

FTB classified SS196 ammunition as not armor piercing.

The FN 5.7 (Fabrique Nationale) pistol is a semiautomatic pistol in 5.7 X 28 mm caliber. [...]

FTB has also examined a 5.7 X 28 mm projectile that FN Herstal has designated the "SS196." The SS196 is loaded with a Hornady 40 grain, jacketed lead bullet. FTB classified SS196 ammunition as not armor piercing ammunition under Federal firearms statutes.

According to FNH USA, FN Herstal tested the SS192 ammunition. SS192 ammunition did not penetrate the Level IIIA vests that were tested. FNH USA states that SS196, Hornady V-Max 40 gr. bullets fired from a 4-3/4 inch barrel did not penetrate the Level II vests that were used in testing.

FNH USA has informed FTB that SS192 is no longer imported for commercial sale to the United States and that commercial sales of 5.7 X 28mm ammunition are restricted to the SS196 (not armor piercing).

I can only imagine how irrirated the ATF must be that they were being flooded with calls over this. Brady claims to have video showing the gun defeating body armory. The AFT meanwhile has numerous scientific studies (that must be done before any gun can be approved for import) that show it doesn't.