Armor Piercing Ammo - Military People - L.E.O.'s


March 31, 2005, 09:17 PM
Could somebody tell me which types of AP ammo exists?
I was wondering also, which types of effects are achieved with the various hardened materials contained within the projectile. I'm going to assume that steel is the lowest form of AP ammo, and I'm also going to assume that depleted Uranium is at the better end of that spectrum.

Are there bullets that explode? Tipped with mercury? Magnesium??
What is the thickest armor that can be penetrated by bullets?
Which caliber bullet is it?
What is the "hardened" core for the best penetration? (Depleted Uranium)?
Do AP bullets explode, or just "punch" through and hit like a regular bullet?

Thanks for the help!

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March 31, 2005, 09:31 PM
Excuse me officer/soldier. Could you tell me what kind of ammo has the best chance of penetrating your protective armor and killing you?


March 31, 2005, 09:37 PM
That's putting words in my mouth and I don't appreciate it. I'd never even consider something so ridiculous....
I'm just wondering because I love the technology behind it. You shouldn't assume, 99.9% of people who post here are VERY responsible firearm owners. Perhaps you should reconsider your statment.


March 31, 2005, 09:43 PM
Most, if not all, military ammo comes in AP. Some of which is illegal for you to own. It usually has a hardened steel core. DU is used in 25mm and bigger calibres. What thickness of armour any of it'll penetrate depends on the calibre and the velocity of the projectile. Rifle calibre AP will not penetrate tank armour, but lighter armoured vehicles, tank tracks and engine blocks will be damaged by it. AP does not explode. It works by being harder than it's intended target.
Ammo that explodes is also 20mm and bigger. No magnesium or mercury though. It's really a small artillery shell with a fuse and a small explosive charge. Mostly used in aircraft cannon and the 25mm chaingun on the Bradley.

Phantom Warrior
March 31, 2005, 09:47 PM

I read this post too and didn't get that interpretation. I think it's a legitimate question and would be curious to know the answer too. It's not as if knowing what makes a good armor-piercing bullet would allow him to go down into his basement and whip up some depleted uranium rounds.

Frankly, most LEO and military body armor can be penetrated by a good rifle round (AP or no), if he was of that bent. Short of tanks or APCs. And if he has the firepower to take THOSE out (rocket launcher or something) you have way more to worry about than him knowing how to make an armor-piercing bullet.

I too believe that perhaps you should reconsider.

March 31, 2005, 09:50 PM
Yeah, I agree....
Most vests out there can be penetrated by .300 winchester magnums and larger.
heh, I wish I had a Rocket Launcher =]
Maybe in Quake 2!

March 31, 2005, 09:52 PM
Shotgunner: Best thing you can do is get a current copy of Cartridges of the World. There is a section which covers military small arms ammuniton to 30MM.

"Are there bullets that explode? Tipped with mercury? Magnesium??"

Generally speaking, explosive ammunition begins at 20MM.

Mercury tipped bullets are not effective.

Magnesium may have been a component of what was known as "headlight" tracers used in WWII on fighter aircraft. The tracing compound was installed in the nose of the projectile, and apparently had a somewhat startling effect on the recipient.

"What is the thickest armor that can be penetrated by bullets?"

Likely, that would be solid shot from a 16 inch naval rifle. Should go through about a foot and a half of steel.

"What is the "hardened" core for the best penetration? (Depleted Uranium)?"

The hardened core, if so equipped is likely to be some sort of a steel alloy-possibly tungsten. Note that steel case rounds are normally made of pretty soft steel, or they would strip the rifling.

Some ammunition, especially using DU use driving bands to engage the rifling, or may be enclosed in a sabot, such as the 120mm rounds for an M-1 Abrams.

The DU rounds, as well as the tungsten variety are called rod or long rod penetrators and punch through the armor.

Another type of armor piercing round is called a HESH, for high explosive squash head-not sure if its used anymore, but was a kind of explosive shaped charge.

March 31, 2005, 09:57 PM
Thanks Delmar!
Nice, I think I'll pick that book up sometime.

Much appreciated

March 31, 2005, 10:24 PM
Okay, Okay. I guess I was thinking too hard or, more likely, not enough. My apologies, I forgot I was among friends. I also have to remember all the people who have gone out of their way here to answer my questions.

March 31, 2005, 10:46 PM
The legal definition for 'armor piercing ammo' is very specific. There is lots of ammo out there that will go through a soft vest, but is not considered AP in the eyes of the law.

US Code Title 18, Sec 921

(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

March 31, 2005, 10:55 PM
You're asking for something that would take a good couple of hours to explain fully; is there any SPECIFIC reason you're asking, or is this just idle curiosity?
I'm a cartridge-collector who also sections ammunition, like so:

All of these rounds are armour-piercing, but some of them are armour-piercing tracers, some are armour-piercing incendiaries, etc. Each round is designed differently, depending on its intended use.

Bear Gulch
March 31, 2005, 10:56 PM
This is one of those situations where Civy and Military nomenclature don't mesh causing heartache. AP in the military world is for use against thinly armored light vehicles and emplacements. AP in Civvyspeak is for punching holes in Kevlar. Fact is there are a lot of center fire rifles that can do that. Many that can't will deliver sufficient blunt trauma to the vest's wearer to render him out of action.

March 31, 2005, 11:03 PM
WOW, SDC very nice pics. They will make for nice desktops. :p

Double Naught Spy
March 31, 2005, 11:13 PM
Most vests out there can be penetrated by .300 winchester magnums and larger.

Given that most vests are kevlar, then most vests can be penetrated by the vast majority of rifle calibers and even the FiveseveN from a pistol. In other words, calibers much smaller and less powerful than the .300 win mag will punch through just fine.

March 31, 2005, 11:19 PM
SDC, those are two great pics. Can you point out which ones are the incendiary and the tracer AP? I've got a few guesses based on tip color but not for the sectioned ones.

March 31, 2005, 11:24 PM
Ok quick and dirty, any calibre can be explosive, you just put explosive in whatever calibre. .50 is the usual starting point, but it's not effective until 20mm or so, like said. DU is just a dense material, like lead is dense, so it retains velocity better than a light material in the face of air resistance (and armor resistance!). Tungsten is dense too, but it's generally inferior to DU, which means depleted Uranium, which should really just be called uranium 238. Uranium 235 is the stuff for making bombs, and they take as much as that out of the ore as they can get, like panning for gold. So DU is U238 and a smidgen of 235 and 234.

Anyway when talking armor penetration they use mm, just a standard thing. Besides that a 16 inch naval gun will pass through slightly more than 1.5 feet of armor. I think it'll pass through more than 1.5 meters of armor. Honestly it's hard to imagine what it wouldn't pass through. Incidentally, naval guns like WW2 shot bullets that were AP and HE, so they penetrate armor and also have explosive in them to blow up just after penetration.

When stuff hits other stuff at really fast speeds (or maybe just high pressures, not sure if time has anything to do with it) materials all seem to act like toothpaste. So when you shoot a .50 bullet at a steel plate the bullet erodes the steel, and the steel flows up around and behind the bullet. Then if it penetrates it can knock off a big chunk with it on the other side, or not, I guess it depends. Also this is how HEAT warheads work. They aren't really hot, though people say they make molten metal that melts through armor thats bull????. it's just a cone of explosive with a thin layer of metal inside it. The explosive detonates, and the thin layer of metal is forced, like toothpaste, into a couple thin steams that hit the armor and erode it. The fast stream of metal moves like 10 000 meters per second, or mach 30, so it's pretty fast - but it only holds together for short distances, less than a few meters. So you hit a piece of armor with a HEAT warhead and there will only be an itty bitty hole in the side, and maybe coming out the other side. And anyone inside is in the way of debris kicking in and out and around at high speeds.

So to stop HEAT warheads they use reactive armor blocks, which are square boxes with a metal tile sitting on some explosive. The HEAT jet hits the box, the explosive underneath the metal tile explodes, the metal tile flies up towards the HEAT stream, and the stream punches through the flying metal tile. However the stream is wobbly now because the tile messed it up, so it doesn't penetrate well when it hits the tank's armor. Also they use electric armor now that requires a lot of electricity, and it just vaporizes the HEAT metal stream with high current.

For AP shells the trick is to get velocity up there, faster and light is better than heavy and slow. So they used to make just ordinary bullet shapes out of steel, but those weren't good enough. So they worked on ways to increase the speed, and came up with a little ridge that runs around the bullet, and it makes the bullet fit into a larger diameter gun. This means the gun can put more pressure on the bullet, and it will go faster. Just before the bullet leaves the muzzle a constriction flattens out the ridge, and you have a smooth, fast bullet. This was just tricky to make, and expensive, so they gave up on it. So in WW2 tanks just shot each other with full-calibre steel projectiles, shaped like the top half of a rocket ship. Then they had problems with steel - it's light so air slows it down faster, and if it hits a really hard armor while it's moving fast it can just shatter on the spot. So they used Tungsten when they could get enough together, and it didn't have either trouble.

Still they had a good material, but they couldn't get the velocity high enough with the propellants they had. If they used any more powder the gun would explode, unless they used the previously mentioned squeeze-bores, and those wore out too fast. So they put a case around a projectile, like a cylinder of wood with a hole drilled down the middle, and then cut in half, and called it a shoe (sabot). They put the bullet in this sabot, and when it shoots down the gun thy can use a lot of powder in a big calibre gun, but when the projectile comes out the wood falls away and a small bullet is travelling very fast.

So they had bullets that are dense and very fast, but they still couldn't go through enough armor. They'd get stopped by 500mm or so. What they did was keep making the bullets longer, longer and longer, so they had a small front surface area but lots of weight on them they would retain velocity REALLY well. Then they found out that they made bullets so long that they couldn't spin them fast enough to keep them pointing forward, and they had to put fins, like on a dart, at the back of the projectile. This meant the bullet wouldn't spin (much) and they made the guns smooth-bore, and the projectiles a few feet long.

english kanigit
April 1, 2005, 01:18 AM
The naval guns can be protected against, if I'm not mistaken.

About 9 or 10 months ago, the history channel did a special on the Bismark. Historians, eye-witness accounts (from the few left), and they even sent a mini sub down to the carcass of the old ship. What they found was fairly supprising. If memory serves correctly, Bismark recieved something like 4,000 or 5,000 naval shells during her last series of firefights. A very large percentage (I'm thinking 50%, maybe more) of the larger caliber shells didn't penetrate Bismark's armour. Granted, a lot of the shells came from smaller ships like destroyers and cruisers, but I believe the majority of the larger shells didn't penetrate.

Not that I'm volunteering to stand behind the metal while you guys take potshots at it! :neener:

Just found this before mashing the "submit reply" button...
Almost two hours had elapsed since the battle had begun, and the Bismarck had shown a formidable capacity of resistance. The British first struck Bismarck at 0902, and ceased fire around 1016. For 74 minutes, the Bismarck received a continuous hammering that no other warship could have taken. We need not forget that the Hood sank six minutes after the first German shells were fired only three days earlier. Moreover, neither the main belt nor the armour deck were seen to be penetrated during the combat, and in the end it was her own crew who scuttled the ship. During this last engagement 2,876 shells were fired at the Bismarck. They are itemised as follows:

380 of 40.6 cm from Rodney
339 of 35.6 cm from King George V
527 of 20.3 cm from Norfolk
254 of 20.3 cm from Dorsetshire
716 of 15.2 cm from Rodney
660 of 13.3 cm from King George V

It will never be known how many of them did actually hit (400, 500, 600, maybe more), but taking into account the short distances in the last phase of the combat, it is assumed that many shells hit.
From, its near the bottom...

english kanigit
April 1, 2005, 01:25 AM
It's my understanding from talking to my dad that the bigger naval guns achieve most of their penetration buy getting something really really big, and reall really heavy up really really high where it can fall really really far and thereby get moving really really fast. Appearently there's just something about a couple thousand pounds of steel flying at several thousand feet per second that most people on the recieving end just wouldn't want to trifle with. :rolleyes: Lord knows I wouldn't... :o

April 1, 2005, 08:47 AM
Somebody ought to do a search of R. Lee Ermy's website for his show Mail Call. I'll bet he's got all of the answers about AP on video with lots of clips from DOD. He probably shoots steel plate behind watermelons!!!

I'm pretty sure I remember watching a segment that he did in response to an email. If not, then I'll bet he would do one in response to an email.


Semper Fi!

(Hand Salute)

Carry On!

April 1, 2005, 12:32 PM
Depleted Uranium is dense, but that is not the reason it is used in penetrators. AP rounds made from DU under go a phenomenon called "adiabetic shearing" when they strike the target - flakes chip off of the outer edge of the front of the projectile (...a gross over-simplification of the process, I know...) This causes two things to happen - the round actually gets sharper, rather than duller, as it fights its way through the armor, and it tends to steer itself into a shorter path through obliquely mounted armor, rather than ricocheting or taking a longer path, as a tungsten alloy round will. If the flakes sheared off enter the target, they catch on fire, and set anything they land on alight, plus there is a slight fissile nuclear yield that contaminates the equipment and sickens any crew that survive the attack.

Battleship AP rounds aren't solid - the ogive is covered by a part called the "windshield", and they actually weigh less than HE rounds for the same gun. Incidentally, the design and performance of battleship HE rounds was highly variable, with the last U.S. design being the best - it had better pentration than the Brittish 16" or even the Japanese 18.1 inch.

April 1, 2005, 12:32 PM
So you hit a piece of armor with a HEAT warhead and there will only be an itty bitty hole in the side, and maybe coming out the other side.Define Itty Bitty... :rolleyes:

As an ex-tanker who fired many a 105 mm HEAT round from and M-60 tank (back in the early 70's) I can tell you that the hole made by that round isn't itty bitty. We fired at both old tank hulls (M-47's, M-48's, many old WWII German Tank hulls and 12" thick battleship armor) on the ranges.

The HEAT rounds always penetrated the tank armor and the resulting hole was anywhere from 1" to 2" in diameter on the entry side. Lots of splash on the exit side. The same rounds dug huge craters out of the battleship armor though they never penetrated and there was no damage to speak of on the backside of the hit.

Oh and HEAT stands for High Explosive Anti-Tank and has nothing to do with the temperature of the round though I imagine that they did produce a great deal of heat on impact.

April 1, 2005, 12:35 PM
...oops, almost forgot. The manual I got for my M1 Garand sez that the standard M2 ball ammo (30-06, 150 grain bullet at 2700 fps), not even the AP version, will penetrate 0.5" of steel armor - I'm betting that will go through just about any vest made.

April 1, 2005, 12:40 PM
"SDC, those are two great pics. Can you point out which ones are the incendiary and the tracer AP? I've got a few guesses based on tip color but not for the sectioned ones."

No problem; in the top pic, from L-R are: 12.7x108mm Soviet API, 50 BMG SLAP-Tracer (red sabot), 50 BMG SLAP (gold sabot), 55 Boys Anti-Tank, 13mm Mauser T-Gewehr, 50 Vickers AP, 4 various 50 BMG AP and API projectiles; 30-06 Springfield M2 AP, 8mm Mauser Smk L'Spur (AP-Tracer), 7.7x56R (.303 Brit.) Italian AP-Incendiary (white phosphorous in a foil capsule around the AP core), and 7.62x54R Russian B32 AP-Incendiary.
All of the rounds in the lower pic are various types of AP, but except for the .38 Special on the top row, far right (Omni-Shock), aren't supposed to do anything BUT pierce armour; the Omni-Shock was supposed to be a "do everything" bullet that pierced armour PLUS expanded into a "propellor" of sorts afterwards.
Bottom pic, L-R; XM645 SPIW flechette, SS109 semi-AP, 357 Mag Arcane copper solid AP, 5.7x28mm FN P90/PDW, 38 Spl tubular bronze PMC Ultramag, 38 Spl Rem FMJ "armour-piercing", 38 Spl early KTW w. steel core, 38 Spl late KTW w. bronze core, 38 Spl AP w. machined steel core, 38 Spl SFM THV (reverse ogive), 38 Spl Omni-Shock, (2nd row) 45 Auto SFM THV, 9mm Luger SFM THV, 9mm Luger "arrowhead" AP, 9mm Luger AP w. machined-steel core in bronze base-cup, and 5.45x18mm PSM AP.

April 1, 2005, 12:51 PM
As far as I know...lvl IV is the only body armor that will defeat a 30-06 AP round. Any center fire rifle round will defeat lvl III body armor. lvl IIIA offers beter protection, but still can be defeated with "off the shelf" rifle ammo.

April 1, 2005, 12:59 PM
You got it backwards. IIIA is less effective than III. Seems like the A stands for 'Almost as good as' :o

April 1, 2005, 01:08 PM
I stand corrected, thanks....

April 1, 2005, 01:18 PM
Maybe I have this wrong, but I understood Level IV to only be available in plate form...specifically 0.5 inch special steel alloy, or 0.75" "Chicken Plate" ceramic. Does one add these plates to the vest, or is this just a rating for vehicle and building armor?

April 1, 2005, 01:44 PM
it's "Hard body armor" you wear it by it's self. Heavy as hell too. You have a front & rear plate. The one I used was 1.5" thick.

April 1, 2005, 02:44 PM
Someone used to make civilian caliber explosive bullets- Hinckley used them (in .22LR) to shoot Reagan and those other people back in 1981. IIRC the bullet that hit Reagan was a riccochet off his limo, and so had already exploded. THe one that hit Jim Brady apparently exploded when it hit his skull, which is why he suffered brain damage but survived. A solid probably would have killed him.

Anyway, I've never seen them for sale anywhere and doubt they're still being made. Even when they were no one had much good to say about them.

April 1, 2005, 04:25 PM
Ja, III is hard armor for rifle threats, IV is hard armour for defeating AP threats. The levels are simply the USA NIJ ones, Europeans use a different standard. Nevertheless level IV doesn't have to be a plate, it can be any form as long as it meets the requisites laid out in the lates (2004) nij standards. One new vest has hundreds of little titanium-ceramic coins all over it, dragonscale or something.

Werewolf, yea maybe ittybitty is bad word, but when you see the silver-dollar hole in an M1A1 hit by a Maverick missile it just seems small!

Rich, yea Uranium combusts when in the presence of oxygen, which is a bonus, and the shearing is nice. However Europeans aren't lazy and they have new tungsten penetrators that shear in a similar manner. Before the tungsten rod would sort of mushroom at the tip. Anyway I think that all penetrators, not just DU ones, 'bite' into sloped armor. It has nothing to do with shear, that would counter the effect, what happens is that the rods aren't actually pointy, that's just a windcap on them. They're blunt at the front, so the windcap falls away and this blunt rod can dig into very sloped armor.

April 1, 2005, 04:59 PM
Someone used to make civilian caliber explosive bullets- Hinckley used them (in .22LR) to shoot Reagan and those other people back in 1981. IIRC the bullet that hit Reagan was a riccochet off his limo, and so had already exploded. THe one that hit Jim Brady apparently exploded when it hit his skull, which is why he suffered brain damage but survived. A solid probably would have killed him.

I have heard that Hinckley used the "devestator" rounds, but I've never seen that confirmed. In any case the one in Brady's head didn't blow up but was pulled out intact, and the one that bounced off the car acted just like any other .22. .22's are notorious for bouncing around inside the body. And when fired out of a small revolver there's every reason to expect only a shallow penetration into a person's skull.

In short, the "exploding" .22's were a novelty item with no practical application. The only practical exploding rounds I've seen this side of a 20mm cannon were on very old elephant gun slugs. The exploding tip on those was designed as a primitive expansion device to force the massive slug open as it impacted. Obviously with smokeless powder and modern materials we don't need anything like that today.

April 1, 2005, 08:19 PM
I hope Teddy Kennedy isn't lurking. You've all just demonstrated utter stoopidity at banning "some" armor piercing, cop killing ammo.

April 1, 2005, 08:42 PM
Waitone-I wouldn't be too concerned about Teddy the Swimmer and the dreaded "copkiller" ammo. He flat wants to ban everything!

April 1, 2005, 09:00 PM
plus there is a slight fissile nuclear yield that contaminates the equipment and sickens any crew that survive the attack.
There is NO fissile yield from a depleted uranium projectile as a result of impact with armor (or anything else). None.

U-238 undergoes EXTREMELY slow alpha decay (not fission), so slowly that it would take several billion years for even half of a given sample to decay into something other than uranium.

Fission in uranium-238 can occur only when the material is bombarded with fast neutrons from some other source (such as the detonation of a thermonuclear secondary). Merely smacking some armor at a few thousand feet per second won't even begin to shake up an atomic nucleus.

In a given sample of uranium, you will have a very small sample of the U-235 isotope that undergoes a TINY amount of spontaneous fission--barely enough to detect with very sensitive instruments. But fission in any very-subcritical mass of uranium is completely and totally negligible.

Like most other heavy metals, uranium IS toxic (so is tungsten), and breathing uranium vapor isn't good for you. But it has nothing to do with nuclear yield, and it would be toxic even if not a low-level alpha emitter.

April 2, 2005, 12:17 AM
I've always been interested in the AP abilities of the ultra-high SD safari rounds. The 170 grain 7mm solids, for example. But I suspect nobody will do the test for fear of the individual with the puffy red face mentioned above.

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