What is Armor Piercing Ammunition?

An AR500 level III steel armor plate.

That seems like a pretty straightforward question, doesn’t it? On the surface, armor piercing ammunition ought to be ammunition that pierces armor, right? Seems pretty simple. Except it isn’t. At least, not according to the BATFE. Under 18 United States code, AP ammo is defined rather arbitrarily as:

(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.

Steel core Norinco 7.62x39mm 123 gr FMJ

And that’s why Norinco steel core 7.62x39mm ammunition was banned from import back in the 90’s, which makes perfect sense because everybody knows that 7.62x39mm is pistol ammo. Wait, is it? According to the federal government, yes. Because handguns exist that will fire it, the BATFE has determined that 7.62x39mm is pistol ammunition. Okay, so it’s kind of goofy to call it pistol ammo, but it is armor piercing, right? After all, it has a steel core.

Wait, so that has to be some really tough armor though, right? Not really. The lightweight polyethylene armor that we used in this test is nowhere near as tough as most other rifle armor. In fact, this steel core ammunition won’t penetrate any armor that is designed to stop rifle rounds. Why not? The feds say that a steel core makes ammunition armor piercing. The steel core in this ammo is very soft steel and it is only used because it was cheaper than lead. Of course, it will easily perforate soft armor. But that is only intended to stop handgun rounds. Any rifle ammunition will do that. So rifle ammunition that can’t actually penetrate rifle armor, is defined by the federal government as armor piercing pistol ammunition. What about pistol ammunition that does penetrate pistol rated armor? Like this Lehigh 10mm? Is this AP ammo?

Soft armor panels

Nope. Not AP. Okay, so this actually is pistol ammo and it did zip right through that level IIIA vest like it wasn’t there. This may give you Forest Whitaker eye to consider, but that is actually not AP ammo. Although it is made entirely of copper, it isn’t beryllium copper, as specified by the statute. It doesn’t meet any of the standards listed above so it cannot be classified as armor piercing ammunition, regardless of how well it pierces armor. But, if I may channel Billy Mays, wait there’s more!

You may recall that the BATFE tried to classify M855/SS109 as armor piercing not too long ago.The justification was a very creative interpretation of the federal statute listed above. Since AR-15 pistols are rather common, they pulled the same trick as with the Norinco stuff and called .223 Rem and 5.56x45mm “pistol ammunition”. M855 does indeed have a steel component in its core, and it is quite a bit harder than the steel used in Norinco 7.62x39mm. But it is hardly “constructed entirely” of steel, as the statute reads. To interpret the statute that way, you would have to define the penetrator (about 1/6 the weight of the projectile) as being the entire “core” and completely disregard the existence of the lead core out of hand. That’s been covered numerous times in other articles and, spoiler: they gave up and stopped trying to take a mediocre 5.56mm load off the market.

Lake City M855 5.56x45mm FMJ

What’s particularly ironic is that, while M855 is not armor piercing ammunition by federal statute, it actually is capable of piercing the very same armor plate that the Norinco 7.62x39mm could not perforate.
I know that this is rather convoluted and it doesn’t get any less so.There are virtually endless variations on this theme. Plain old lead core 55 gr M193 5.56mm (also not AP by federal statute) can generally perforate steel level III plates, while M855 is easily stopped. That’s because, when it comes to steel armor, velocity matters quite a bit more than bullet construction.

Then there is the military definition of “armor piercing” which is pretty much any ammunition designed to meet a standard in perforating a particular type of armor at a specified distance. Some level III+ steel plates can stop P60 or P80 7.62x51mm, which are actual, military AP ammo type classifications but

M80A1 7.62x51mm Enhanced Performance Round

M855A1 EPR or M80A1 EPR, which are not AP (according to DoD or federal statute) can cut through it like it’s not there. And, of course, the NIJ level IV standard is defined by the ability to stop .30-06 M2AP, which was not only designated by the military as armor piercing, but also meets the federal definition . This projectile was widely used during WWII. It was actually issued exclusive of M2 ball for much of the war because it was relatively cheap, highly penetrative, and had great terminal effect, so there was little advantage in complicating the supply chain with two different types of ammunition. There are multitudes of anecdotal reports of Joes preferring M2AP and extolling its virtues in digging through trees and other obstacles to root out the Jerrys.

Come And Take It NIJ level IV stand alone armor plate

The fun part about that is that many of the ammunition types that the military classifies as AP would actually meet the federal statute, if the BATFE were inclined to classify them as being intended for use handguns. Somehow, I don’t think that the preposterous nature of a .30-06 pistol would bother the BATFE.

The takeaway is that, just as there is no such thing as a “bulletproof vest,” there is also no such thing as “armor piercing” ammo. At least insofar as there is always something that can stop it. If wearing armor is part of your job, it is strongly recommended that you learn the limits of your gear. Likewise, if you rely on a firearm for defense, it is wise to know what it can do against barriers and body armor.


Andrew is a combat veteran of OEF and has performed hundreds of ballistic tests for his YouTube channel, The Chopping Block (https://www.youtube.com/user/chopinbloc). He is an avid firearm collector and competitor and lives with his family in Arizona. If you have any questions, you may email him at choppingblocktests@gmail.com


  • Nicholas C

    Actually speed kills armor. I have been testing some very strong steel armor and while steel core and even .50bmg didnt do much to it, Rem 300RUM cut through like a laser.

    • Chop Block

      Generally, yes. Depends on the type. As you can see with the UHMWPE plate, the M855 was able to get through, despite being slower than M193, which was stopped.

    • BillC

      “That’s because, when it comes to steel armor, velocity matters quite a bit more than bullet construction.”

    • Slvrwrx

      Steel Armor that stops .50 BMG :O

      • Gary Kirk

        It’s out there, but the trauma of being smacked by a 50 would probably still cause some minor irritation..

        • The amount of steel needed to stop .50BMG is going to be insanely heavy. I’m also pretty sure that distance to stop it, is going to be many many yards away from the muzzle 😀

          • Gary Kirk

            Yeah, well seeing as how 50 bmg is still packing more energy @ 2000 yards than a 5.56 is @ the muzzle.. You’d be in for a hurtin for a good long ways..

      • Chop Block

        I’m guessing he didn’t mean steel BODY armor.

      • phuzz

        Does a tank count as body armour?

        • The Brigadier

          You will need a M1 Abrams. Lighter tanks will still be holed by .50 BMG AP.

      • The Brigadier

        You can make anything thick enough and it will stop most any small arms projectile. .50 BMG armor piercing rounds will go through up to 58″ of building material. It will hole armored personnel vehicles and many light tanks. You can thicken the plating to defeat that round, but the expense will be much greater.

        • I have an 11lb piece of body armor that supposed to stop 50 BMG 🙂 That will be an interesting test.

    • gordon

      Funny you should mention that, I am building a falling block bullpup .300 RUM with a 29.5″ barrel for the purpose of defeating rifle plates. I intend to experiment with different bullets, a few of my own construction. According to QuickLoad M80A1 will likely be pushed to about 3650fps. It’ll be interesting to see how that bullet fares at that speed.

      • I’m able to hit 3450 from a .300 WM with the M80A1 bullet.

      • Chop Block

        So much awesome! Please email me at chppingblocktests@gmail.com when it is finished. I’d love to see your testing.

        • Troy Lund

          You guys should try moly-coating these projectiles. Higher velocity without increasing chamber pressure. Don’t know anything else that can do that.

          • Troy Lund

            Moly coating will also reduce wear when firing “:barrel-burners” like the RUM.

          • Velocity gains on moly coated bullets is minimal.

          • Jeremy Nettles

            “Minimal” is an exaggeration, but certainly “marginal.”

          • The Brigadier

            Yeah, but moly coated bullets will double the life of the barrel and if for no other reason it should be used.

          • Quest

            Sabot… but a M855A1 or M80A1 in .338LM .416cheytac or .50bmg and fine powder = pure lasers

          • But getting accuracy out of those loads isn’t going to be the greatest..

      • John Yossarian

        Maniac! Because of you, there’s now an extra splotch of camo on my tactical pants. (credit:TYM)

      • wetcorps

        I’d like to see this on TFB when you’re finished.

      • iksnilol


    • Jeff Heeszel

      Usually, but we put holes through AR500 with a carbide core shotgun slug, at only about 1200 fps. Hardness kills armor too.

  • Ark

    I’m okay with the general policy decision of prohibiting armor piercing ammunition, but clearly the current definition is bass-ackwards. Shooting out of a very short rifle doesn’t make it no longer “rifle ammunition”. Switch to a military definition or a definition based on objective, tested penetration capability.

    As far as I’m concerned, AP ammo is one of those things that really has no purpose on the civilian market besides equipping mass shooters to defeat armor, and being a toy for rich people and Youtubers. My heart is certainly not breaking over not being about to spend $2 a round on something that makes the exact same hole in a sheet of paper. If you “need” it for “defense” against somebody wearing a plate carrier, you’re probably doing something very, very wrong.

    • Matt Roth

      yes, because we all know NO bad guys buy armor plates or vests…

    • Drew Coleman

      When has AP ammo ever actually been a problem or been in use by criminals? Why should we ban something just because it’s capable of being misused? Why shouldn’t I have body armor if I want to pay for it?

    • John A. Smith

      Your argument about need is the same for “assault” rifles, handguns, and virtually every other weapon on the planet.

    • Chop Block

      The reason for our Second Amendment is to ensure civilians have state of the art military arms and munitions.

    • RSG

      Your screed overlooks the entire premise of the second amendment’s purpose. It has nothing to do with hunting or target practice. It exists primarily to resist tyranny. What that would look like today is govt folks, wearing body armor, enforcing tyranny. That alone is reason enough for We the People to have unfettered access to any caliber AP ammo we desire. It’s really that simple. Either you support the 2A as intended, or you don’t.

      • nonobaddog

        And that says it like it really is. Yes.

    • Ebby123

      “If you “need” it for “defense” against somebody wearing a plate carrier, you’re probably doing something very, very wrong.”


      (Note the complete absence of an explanation for needing AP ammo – because I don’t owe you one.)

    • SPQR9

      You completely miss the entire point. “AP” ammo is just cheap rifle ammunition. The law was intended to benefit police wearing light armor protection designed to protect against common pistol calibers. Almost ALL rifle ammunition defeats such protection.

      Once you start banning rifle ammunition of one type, you have no rational place to stop.

      By the way, when the proposed ATF ban of M855 was being discussed a couple of years ago, it was revealed that there has never been a police officer killed in the US because his vest was penetrated by 5.56mm M855. In fact, I would have to double check but I think there was only one police officer killed with 5.56mm/.223 Rem caliber rifle in the previous decade.

    • john huscio

      Looks like we’ve got a fudd……..you do know all rifle ammo is armor piercing….

  • GR Arnold

    More proof the NFA needs to be fully overturned. They more they add to it the dumber the whole damn situation gets. Pathetic.

    • Chop Block

      I concur, but the ban on making and importing AP ammo isn’t part of the NDA.

      • The Brigadier


    • Joseph Goins

      How is this related to the NFA? It isn’t. You are blindly spewing out pro-gun stances without any thought behind them.

      • john huscio

        “You are blindly spewing out pro-gun stances without any thought behind them.”

        A rather bizarre thing to read on a gun oriented website……

        • Twilight sparkle

          Doesn’t make it less true. Seems like tfb picked up a lot of less informed people around last shot show and they’ve been muddying up the content here.

          • Edeco

            I’d’ve pointed to a different recent event…

        • Joseph Goins

          It’s about intellectual honesty. While I am against banning anything (especially something as ridiculous as armor piercing ammo), I can’t tolerate the hypocrisy that comes from our community. Whenever anti-gun statements come out, we tend to pounce on things (“clips” instead of “magazines”) and say that the person making the statement needs to do their research. It cuts both ways.

  • IMO, anything related to “AP” ammo simply needs to be in regards to additional charges filed upon someone when they commit a crime. As Andrew points out, there’s always a bullet type/caliber out there that will defeat the different levels of armor worn by LEO/Mil.

    • Drew Coleman

      I just don’t get why using AP ammo would be worse than having shot someone to begin with.

      • I guess the gov’t likes more laws? 😀 But yeah I totally agree. “Bad Guy” wants to do harm to someone is more than enough reason to put them away 😀

        • Drew Coleman

          I’d just as soon as not regulate it unless it’s actually a problem. Most people aren’t going to buy real AP ammo since it’s more expensive and it’s just a novelty most of the time.

      • Jeremy Nettles

        It’s all because cops wear body armor. A few decades ago, when this trend started, the general idea was that body armor would make LEO’s impervious to bad guys’ bullets. From there, the idea of “armor piercing” and “cop-killer” bullets was startling to people who didn’t know any better, and a toehold was opened up for those who’d just as soon ban private gun ownership altogether.

        Ignoring the absurdity of a criminal choosing to shoot at the cops with ball or hollow-point ammo because AP rounds would be illegal, this just shows what happens when gun-grabbers are allowed to write the rules.

        • AnonyMouse

          It doesn’t show what happens when “gun-grabbers” are allowed to write the rules, because if the people writing the rules really wanted a total end to civilian gun ownership, they would have done a hell of a lot more than just ban an oddly specific yet nebulous category of ammunition.
          No, this just shows the kind of stupid bullshit that comes up when the government caves to kneejerk anxieties from people who don’t actually have any knowledge of the area in question. There are similar examples of regulations being put into place or removed in the exact same stupid manner for the exact same stupid reason in nearly every single part of the government.

          • Jeremy Nettles

            “No, this just shows the kind of stupid bullshit that comes up when the government caves to kneejerk anxieties from people who don’t actually have any knowledge of the area in question.”

            Isn’t that what I said?

          • AnonyMouse

            Not exactly. You described the legislators as “gun-grabbers,” which implies malice from the government rather than ignorance from the public. In addition, your post was written as if that issue was specific to firearm rights alone, which it isn’t.

          • Jeremy Nettles

            You read it that way because you (apparently) think gun-grabbers are by nature malicious. By and large, this is not true—people who want to ban guns and people who want to de-regulate guns are, with few exceptions, aiming at the same thing: increased public safety. It’s just that the great majority of gun-grabbers, both in the public and in the legislature, are ignorant, so their benevolence becomes maleficence. They’re not malicious, in that they don’t intend harm, just maleficent, in that they actually accomplish harm, due to their well-meaning ignorance. And we’re back where we started. When gun-grabbers (including the ignorant public and their proxies in the legislature) are allowed to write the rules, these are the kind of boneheaded rules we get.

            Also, it’s not necessary for me to address every application of the problem of public/legislator ignorance, in order for my statement to be true. It’s a firearms site; it applies to (among other things) firearms. How silly would it be for me to complain that “your post was written as if the issue were specific to government alone, which it isn’t”?

          • AnonyMouse

            I apologize. The main reason that I interpreted “gun-grabbers” as having malicious connotations is because I have heard similar language used to imply that “the government wants to take all our guns so that we’ll be unable to resist when they start their evil plans” or something like that. While I know that isn’t the perspective of the majority, it is still the perspective of an incredibly vocal minority.

            The main reason that I emphasized the fact that it was a broader issue is that the transitive property, while still factually correct, can be used to convey a misleading subtext. For example, poor people are more likely to commit crimes, and African Americans are more likely to be poor. While it would be factually accurate to cut out the middleman and say that African Americans are more likely to commit crimes, it would be misleading, because it would imply that African Americans are the source of the problem, rather than poverty in general. Therefore, by only mentioning this specific facet of the problem, you emphasize and isolate that particular component, making it seem as if it exists in a vacuum. I understand why you didn’t include that in your initial post, but I hope you also understand why I felt the urge to clarify.

          • Jeremy Nettles

            Apology accepted. 😛

            All kidding aside, I was pretty sure we agreed on everything but terminology. Happens.

        • Cymond

          a criminal choosing to shoot at the cops with ball or hollow-point ammo because AP rounds would be illegal aren’t available to purchase

          Seriously, I don’t support gun bans in general, but the average street thug isn’t going to be able to get ahold of AP ammo smuggled from another country.

          • Jeremy Nettles

            Agreed, but a motivated thug will always find some way to accomplish what he wants, and since the regulation defines ‘armor piercing’ in a rather idiotic fashion, it’s not all that difficult.

  • USMC03Vet

    It’s easier to just make s*** up.
    – ATF

    • Ebby123

      Who’s got time for Science?

      • “DJT”

        Stinking since, tuu complicated and tuu much words to twitter it. Since is for Loosers, Sad.
        #FillTheSwamp #climateChangeIsMadeUpByChina,evenToughAllOfMyMinistersDisagreeWithMe

        • Ebby123

          Er… wut?

      • Pumpkin King XXIII

        Ain’t nobody got time for that!
        Unless you get pinched by atf for something and your equipped to pay an attorney and then atf offers a deal to plead to something else with no jail time and the lawyers tell you this is a good safe deal. lot better than taking the chance of 10 years.
        ATF is happy because they get to keep making arbitrary rules without repercussions and the attorney is happy cause he got paid, client is sad but not so much as spending 10 years in jail.

    • “DJT”

      I 100% agree

    • The Brigadier

      That’s why you Marines are called Jarheads. Look it up moron.

  • thedonn007

    Full lead M193 is more AP then M855 with the steel core.

    • Chop Block

      For steel armor. Exact opposite for the UHMWPE used in the test above.

  • SlowJoeCrow

    In the US, unfortunately “armor piercing” is anything an ATF agent doesn’t like. There was an incident recently where the ATF went after a company that made lathe turned brass bullets for target shooting.

    If it can be used to whip up publicity and expand government power it will be banned. Look at the “switchblade” laws still on the books from 1950s “greaser” panics, or New Jersey’s hollow point ammunition ban. For that matter a New Jersey state legislator recently put up a bill to criminalize possession of AP ammo for the FN Five Seven, because apparently making something already illegal on the federal level even more illegal will stop gang violence in Newark.

    • john huscio

      The switchblade bans are falling one by one thanks to kniferights.

  • Rnasser Rnasser

    Wouldn’t be more scientific to classify each ammo by actual performance (under certain standards), not bullet looks, materials, or construction?
    Performance of any ammo depends on the distance, angle of impact, the type of armor, the bullet type, and the muzzle velocity. If you want to get fancy add repeated impact standard, close to the edges, etc.

    • Drew Coleman

      If there was a real need to regulate it, then yes it should be by performance. But I just don’t see the need for regulation in this case.

      • Rnasser Rnasser

        But… but… the kids! 🙂

  • Mystick

    This is one of the many reasons the BATFE needs to be gutted and restructured.

    • Chop Block

      You spelled “eliminated and forgotten” wrong.

      • Mystick

        I see what you did there 😉

  • derfelcadarn

    Magnum Research’s Lone Eagle was not preposterous, and was a hell of a gun to shoot.

    • Chop Block

      Yeah, that was a really popular carry pistol for police and armed citizens, wasn’t it?

  • noob

    hmm so that means the best AP “pistol” set up would be one of those “firearms” like the XO-26b which has a 26″ oal for a long-ish barrel but still being lighter up front and more handy than a 16″ barrel rifle. Load it up with 55gr solids copper 5.56mm at 2700fps, slap on a red dot and engage at less than 50m.

  • Charles

    Adding Soviet 7N6 to the rolls of armor-piercing due to it’s steel content was done SOLELY to demonize the cheapest plinking ammunition in this country. The cost per round went up nearly double almost overnight and stranded container loads of already paid-for merchandise outside the realm of lawful resale.
    This was done by the past administration and their lackeys to simply make the shooting sports more expensive and was a thinly veiled attempt to drive some importers/resellers into a bankruptcy situation with very little effort or expense to the gun-grabbers.

  • Uniform223

    Liberals: guns are bad
    Democrats: guns are bad
    BATFE: guns are bad
    Vast majority of celebrities: guns are bad
    Communists: guns are bad
    Facists: guns are bad

    That to me sums it up…

    • jcitizen

      idiots: guns are bad
      That pretty well sums it up for me.

    • Wow!

      And the irony is that everyone on that list historically and currently loaded up armed to the teeth while saying it…

  • Sid Collins

    I am looking to acquire a pulsed plasma rifle in the 40 watt range, but I don’t know if it will defeat Level III body armor.
    Seriously though, I am having trouble finding a reason to regulate AP ammo. LEOs will not typically wear any level of armor that will stop traditional rifle ammo. The distinction made in the military has little bearing on regulations.

  • Earl

    Try a .378 Weatherby magnum on that plate

  • Thomas Donohue

    New armor coming soon .” Foam steel ” Back to the drawing boards again !

  • The Brigadier

    Inexpensive graphene should be coming to market soon and it will used for the highest grade body armor. Graphene is 22.5 times harder than the strongest tool steel, and its also over 10 times stronger than beta titanium that is beaucoup expensive. An inch thick plate of graphene armor will even stop .50 BMG, but the shock of it will kill you anyway. Still, this will replace aramids (Kevlar, Goldweave etc.) and molecular polyethylene. Its also much lighter than both as the adhesive film that binds the graphene 1mm layers is much lighter than urethane that binds the aramids and will be much lighter than even the light polyethylene. Just in time for the rail gun rifles that will be coming soon. Science marches on.

    • Chop Block

      Where are you getting this information? It sounds highly speculative. Also, if a plate stops .50 BMG and there is not excessive back face deformation, the shock will NOT “kill you anyway”. The energy delivered to the target is no greater (slightly less, actually) than the energy delivered to the shooter.

  • Chop Block

    Not an ideal projectile material, though. Too light.

  • dunhillmc

    The federal AP ammo law was written for handgun ammo that was made to
    penetrate soft body armor. It has zero to do with the military
    definition of of AP ammo which is made to penetrate metal armor

  • jimmyjet

    That POS outfit “Olympic Arms” was aware that if they produced an AK pistol in 7.61×39 the steal insert version of the ammo would be banned from import. They went right ahead and did it and…….the ammo was banned. Presto-chango, NO MORE CHEAP CHINESE AK AMMO!