Originaley posted in the Maintenance & Cleaning section by FAT-T.  

What is the differnce between a solid jacketed bullet and an armor piercing bullet? Is the design different? What is the make up and difference? Do they both have lead for a core and is the compound of the lead the same or do they have more antimony in the lead compound? or are they soild steel? If so then how are they able to get the stability and the velocity of a steel slug that weighs lighter then a lead slug which is heaveier?      

Full metal jacket is usually a copper jacket over a lead core, armor piercing has a heavy hardened steel core, we used to shoot 30 cal AP bullets, dig them out of the earth backstop, strip off the copper jacket and we had a needle point hardened steel punch, a very short punch but very useful for a point to start a drill, or peening a screw.

This may have changed, but this is the way they used to be made, you know, back in the olden days! [:)]

Aren't there steel core armor piercing bullets? My friend that originally posted this thinks there is no such thing because he thinks they are to lite and won't stabilize in flight. He thinks armor piercing is a bullet with a steel penetrator and lead behind it. But the only bullet I know that is like that is SS109/M855, and the BATF does not consider this round armor piercing? What's inside the core of a Black tip 30-06, or an armor piercing .50 BMG?                

   

See here for the 30-06: [url]http://www.cartridgecollectors.org/30-06intro/[/url], pics and info.

Mike

Here is a photo of a 30 cal AP bullet and it's steel core.

Bullet weight is 163 gr
Core weight is 78 gr
Core diameter 6.25 mm

This bullet is probably WW2 or Korean War vintage.

[img]http://www.pbase.com/image/23653151.jpg[/img]

Thanks! In that pic is there any lead behind that steel core? Or is it just the steel core and copper jacket?  

I've seen the AP .50 and it's just like the above .30, just bigger of course. Pretty sure it's just a steel core, and the copper and lead strip away upon impact. I think I have one thats kind of half stripped laying around somewhere, if I can find it I'll post it later.

Steel core and copper jacket, that's all.  To give you an idea of how hard that steel core is, it was recovered from a dirt backstop, the jacket was torn a bit and peeled off with pliers, I have used that point to make dimples in steel to start drilling a hole, I have used it for that purpose dozens of times and it's still like a needle on the end.

Merely having a steel core does not always mean it's an "AP" round. It may perform better than an equivalent lead cored projectile, but compared to a dedicated AP projectille  it may fail miserably.

The US Cal .30 AP round is still a standard by which many are compared. Early lots posessed tungsten, later lots used hardened steel. Both had the unusual tendency to penetrate better at 300 yards than it did at 100 yards..(Had to do with the round having stabilized..)

Meplat-

Thanks guys,

Troy, how many yards away were those steel targets at? I thought AP.50BMG would go straight through just about anything.  

I have some information that some might find interesting.

Having a stash of the 163grn 30cal. AP bullet heads I have done a bit of reloading and testing for the purposes of furthering my understanding/education.

Not really wanting to type it all out again I'm simply going to point you to here...

[url]http://www.thehighroad.org/showthread.php?s=&threadid=47472[/url]


I've loaded the 163grn AP pulls into a 300WinMag and the muzzle velocity is likely right at 3200fps after stopping at a near max load of IMR4138.   Reckon that my 300WinMag is giving a good 300-400fps more velocity to the same bullet than an old 30-06 could manage.

Also, I have tested the 150grn AP bullet in my 300WinMag that came from the 7.62Nato round.

My results are sumarized on the link provided above and gives a description of the bullets after having cross sectioned them.   BOTH the 163grn and the 150grn rounds have lead inside their jackets, the real reason it's there I don't know other than perhaps trying to optimize a bullet's length for a specific twist rate in a barrel(depending on core density, steel alloys being less dense than lead and tungsten cores being more dense).



As for the ability of the rounds penetrating at distance compared to close range due to the fact that they have stabilized.... That is something I may have to test, though I have the 163s punching a hole in 1 1/4 inch plate steel at a distance of around 80 yards.    I know that the 150s are pathetic in comparison to the 163s, the 150s use a lower quality core material that apparently is melting upon impact thanks to my spanking them so hard with my 300WinMag.

You said the 163 gr bullet had lead in front of the core, I didn't see any, but the bullet wasn't totally intact when I recovered it, and I haven't sectioned an unfired one.  I believe the core is hardened steel, it is attracted to a magnet, I'm not sure if the Tungsten would be or not.

Yes, there is lead in the front of the 163grn AP bullet, it's not much but it is there.   I've cross sectioned both the 150grn. and the 163grn bullet, the location of the lead is reversed for the 150grn bullet.

Here is an old and shitty pic,
[img]http://home.bak.rr.com/varmintcong/APplate/apcutaway.jpg[/img]

I need to get better lighting for decent contrast to show it more clearly.    Will post pics of both bullets I sectioned once I manage to get ahold of some more batteries for my digital camera and get some decent pics.

Read this for legal description of "Armor Piercing".

[url]http://www.atf.gov/firearms/legal/armor.htm[/url]

MM

It says that:

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

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

U.S. .30-06 M2 AP, Identified by a black coating on the projectile tip. [/b]


Everything else is... well you know...

Uglygun, did you get any batteries for your digital camera yet. I'd like to see the pics of the sectioned 163s and the 150s.

Why is the lead reversed in the two rounds?