Posted this in the GD but thought people here might be interested

www.atf.treas.gov/firearms/legal/armor.htm

Legal > Armor Piercing Ammunition

Under Title 18, UNITED STATES CODE, CHAPTER 44 as amended by Public Law 103-322
The Violent Crime and Law Enforcement Act of 1994 (enacted September 13, 1994) 18 U.S.C. CHAPTER 44 § 921(a)(17)(B) the term 'armor piercing ammunition' means --

(i) a projectile or projectile core which may be used in a handgun and which is constructed entirely (excluding the presence of traces of other substances) from one or a combination of tungsten alloys, steel, iron, brass, bronze, beryllium copper, or depleted uranium; or

(ii) a full jacketed projectile larger than .22 caliber designed and intended for use in a handgun and whose jacket has a weight of more than 25 percent of the total weight of the projectile.

(C) The term 'armor piercing ammunition' does not include shotgun shot required by Federal or State environmental or game regulations for hunting purposes, a frangible projectile designed for target shooting, a projectile which the Secretary finds is primarily intended to be used for sporting purposes, or any other projectile or projectile core which the Secretary finds is intended to be used for industrial purposes, including a charge used in an oil and gas well perforating device.

§ 922(a) It shall be unlawful --

(7) for any person to manufacture or import armor piercing ammunition, except that this paragraph shall not apply to --

   (A) the manufacture or importation of such ammunition for the use of the United States or any department or agency thereof or any State or any department, agency, or political subdivision thereof;
   (B) the manufacture of such ammunition for the purpose of exportation; and
   (C) any manufacture or importation for the purpose of testing or experimentation authorized by the Secretary; and

(8) for any manufacturer or importer to sell or deliver armor piercing ammunition, except that this paragraph shall not apply to --

   (A) the sale or delivery by a manufacturer or importer of such ammunition for the use of the United States or any department or agency thereof or any State or any department agency, or political subdivision thereof;
   (B) the sale or delivery by a manufacturer or importer of such ammunition for the purpose of exportation;
   (C) the sale or delivery by a manufacturer or importer of such ammunition for the purposes of testing or experimenting authorized by the Secretary.

(b) It shall be unlawful for any licensed importer, licensed manufacturer, licensed dealer, or licensed collector to sell or deliver--

(5) any firearm or armor-piercing ammunition to any person unless the licensee notes in his records, required to be kept pursuant to section 923 of this chapter, the name, age, and place of residence of such person if the person is an individual, or the identity and principal and local places of business of such person if the person is a corporation or other business entity.
§ 923

(a) No person shall engage in the business of importing, manufacturing, or dealing in firearms, or importing or manufacturing ammunition until he has filed an application with and received a license to do so from the Secretary... Each applicant shall pay a fee for obtaining such a license to do so from the Secretary... Each applicant shall pay a fee for obtaining such a license, a separate fee being required for each place in which the applicant is to do business, as follows:

   (1) If the applicant is a manufacturer-

       (A) of destructive devices, ammunition for destructive devices or armor piercing ammunition, a fee of $1,000 per year;

   (2) If the applicant is an importer-

       (A) of destructive devices, ammunition for destructive devices or armor piercing ammunition, a fee of $1,000 per year.

           (e) ...The Secretary may, after notice and opportunity for hearing, revoke the license of a dealer who willfully transfers armor piercing ammunition...

           (k) Licensed importers and licensed manufactures shall mark all armor piecing projectiles and packages containing such projectiles for distribution in the manner prescribed by the Secretary by regulation. The Secretary shall furnish information to each dealer licensed under this chapter defining which projectiles are considered armor piercing ammunition as defined by section 921(a)(17)(B).

§ 929(a)

(1) Whoever, during and in relation to the commission of a crime of violence or drug trafficking crime (including a crime of violence or drug trafficking crime which provides for an enhanced punishment if committed by the use of a deadly or dangerous weapon or device) for which he may be prosecuted in a court of the United States, uses or carries a firearm and is in possession of armor piercing ammunition capable of being fired in that firearm, shall in addition to the punishment provided for the commission of such crime of violence or drug trafficking crime, be sentenced to a term of imprisonment for not less than five years.

   (b) Not withstanding any other provision of law, the court shall not suspend the sentence of any person convicted of a violation of this section, nor place the person on probation, nor shall the terms of imprisonment run concurrently with any other terms of imprisonment, including that imposed for the crime in which the armor piercing ammunition was used or possessed. No person sentenced under this section shall be eligible for parole during the term of impressment imposed herein.

List of Armor Piercing Ammunition

bullet KTW AMMUNITION, all calibers. (Identified by a green coating on the projectile)

bullet ARCANE AMMUNITION, all calibers. (Identified by a pointed bronze or brass projectile)

bullet THV AMMUNITION, all calibers. (Identified by a brass or bronze projectile and having a headstamp containing the letters SFM and THV)

bullet CZECHOSLOVAKIAN manufactured 9mm Parabellum (Luger) ammunition having an iron or steel core. (Identified by a cupronickel jacket and headstamp containing a triangle, star and dates 49, 50, 51, or 52. The bullet is attracted to a magnet)

bullet GERMAN manufactured 9mm Parabellum (Luger) having an iron or steel bullet core. (Original packaging is marked Pisolenpatronen 08 m.E. May have black colored bullet. This bullet is attracted to a magnet)

bullet MSC AMMUNITION, Caliber .25. (Identified by a hollow point brass bullet. NOTE: MSC ammunition Caliber .25 identified by a hollow point copper bullet is not armor piercing)

bullet BLACK STEEL ARMOR PIERCING AMMUNITION, All Calibers, as produced by National Cartridge, Atlanta, Georgia.

bullet BLACK STEEL METAL PIERCING AMMUNITION, All Calibers, as produced by National Cartridge, Atlanta, Georgia.

bullet 7.62mm NATO AP (Identified by black coloring in the bullet tip. This ammunition is used by various NATO countries. The U.S. military designation is M61 AP)

bullet 7.62mm NATO SLAP (identified by projectile having a plastic sabot around a hard penetrator. The penetrator protrudes above the sabot and is similar in appearance to a Remington accelerator cartridge)

bullet PMC ULTRAMAG .38 Special caliber, constructed entirely of a brass type material, and plastic pusher disc located at the base of the projectile. NOTE: PMC ULTRAMAG 38J late production made of copper with lead alloy projectile is not armor piercing.

bullet OMNISHOCK, a .38 Special cartridge with a lead bullet containing a mild steel core with a flattened head resembling a wad cutter. (NOTE: OMNISHOCK cartridges having a bullet with an aluminum core are not armor piercing.)

bullet 7.62x39mm with steel core. (NOTE: these projectiles have a steel core. Projectiles having a lead core with steel jacket or steel case are not armor piercing)

NOTE: THE FOLLOWING CARTRIDGES HAVE BEEN REMOVED FROM THE DEFINITION OF ARMOR PIERCING AMMUNITION:

bullet 5.56MM (.223) SS109 and M855 Ammunition, Identified by a green coating on the projectile tip.

bullet U.S. .30-06 M2 AP, Identified by a black coating on the projectile tip.

My 9mm depelete uranium hardball is illegal?
Too bad I lost it all in the last hurricane.
I sill have some DU hollow points which seem to be legal.

I always thought that the SS190 may be OK for the same reason SS109 is OK: core is made up of two materials.  Steel & lead for SS109 - Steel & Aluminum for SS190.

The one section that might get the SS190:
"a full jacketed projectile larger than .22 caliber designed and intended for use in a handgun and whose jacket has a weight of more than 25 percent of the total weight of the projectile."  Since Aluminum is a lot lighter than lead, the copper jacket may meet this section.  I don't know if the jacket comes close to the 25%. May be some else can determine the mass of the three parts of the bullet.

I've never seen the SS190 being sold for civilian consumption......FN was advertizing this round as AP......

Quoted: I've never seen the SS190 being sold for civilian consumption......FN was advertizing this round as AP......

The manufacturer's intent or whether the manufacturer has voluntarily decided not to sale to civilians is not important. It’s the legal definition as written above that matters to the ATF.  

The SS109 was designed to improve Armor Piercing capabilities.  However, it did not meet the legal definition of AP due to the dual core. So, according to the ATF it is not an AP round.  Similarly, the SS190 is dual core & doesn’t meet the requirement of (i). I don’t know if it meets the requirement of (ii)

Quoted: I always thought that the SS190 may be OK for the same reason SS109 is OK: core is made up of two materials.  Steel & lead for SS109 - Steel & Aluminum for SS190. The one section that might get the SS190: "a full jacketed projectile larger than .22 caliber designed and intended for use in a handgun and whose jacket has a weight of more than 25 percent of the total weight of the projectile."  Since Aluminum is a lot lighter than lead, the copper jacket may meet this section.  I don't know if the jacket comes close to the 25%. May be some else can determine the mass of the three parts of the bullet.

Isn't SS190 a .22 caliber round?