What's the difference 'tween AP and steel core bullets?

[Buckskinner]

If surplus ammo "attracts a magnet", what is the actual difference between the construction of steel core bullets and AP bullets?

Seems to me there could be some leeeegal issues 'round this one...

 

[000Buck]

Some AP rounds have a tungsten core. But I think the old M2 blacktip are just super hardened steel, while the stuff you can buy now is like soft matchbox car steel.

 

[Cableman]

This is a 163 grain AP bullet I cut into.

 

[Buckskinner]

What did you use for disassembly?

Have you done that on other Non AP surplus?
What is "hardened" vs. unhardened.?
As is what will it penetrate and to what extent?

Enquiring minds and all that...

 

[bernie]

"Attracting a magnet" is not necessarily indicative of a steel core. Much surplus ammunition is steel jacketed. Recently, the Civilian Marksmanship Program was sending out .30-06 surplus that had a mild steel jacket. It attracted a magnet, but it was not armor piercing or steel cored. I might also add that it shot pretty well too!

 

[Grump]

Almost all M2 Ball I've seen, from WWII stuff by [whomever] to Lake City in the late '60s, is steel jacketed with the gilding metal plating.

Careless talk by others saying "no steel core" for their rifles, is usually, IME, referring to jackets.

The .30-06 AP had the "boat tail" to the steel penetrator to reduce mass back there, and reduce/eliminate a tendency to snap when hitting and penetrating armor struck at an angle (like most of the time). Some odd physics and inertia effects resulted in the steel cores turning on impact and penetrating almost perpendicular to the armor's slope. They will penetrate at least 1/2 inch of unidentified but probably middle-mild steel plate, in my personal experience. There's some military performance standard out there somewhere.

The 7.62mm NATO AP was just enough lighter that they could leave the penetrator flat-based. The old '06 penetrators make great center-punches for dotting HARD steel.

The M855 stuff uses a regular steel penetrator, as does the Russkie 5.45mm round, if my sources are correct. Neither is really up to being called AP, though they both do very well on old GI steel pot helmets at extended ranges.

 

[Ian]

Buckskinner - Steel varies in hardness depending on composition, heat treating processes, and other things. AP steel cores are very hard, so that they can push through things without deforming. Non-AP steel-cored ammo uses softer steel thatwill deform more easily (and thus penetrate less) for reasons of weight, economy, and such.

 

[Buckskinner]

Got it.

Thanks for your help.
I especially appreciate the lowdown on the cmp ammo...

 

[capt_happypants]

To confuse matters more, BATFE does not consider M2 30-06 and M855 5.56mm to be AP. Anything that can reliably zip through a steel helmet at 300 yards might be effective against soft or hard armor.

 

[Jim K]

There is steel jacketed ammunition, with lead core, like most U.S. GI 30-'06 and 7.62 NATO, used to save copper.

There is ammo with both steel core and steel jacket, like much German WWII ammo, used because of the scarcity of lead and copper.

There is armor piercing ammo, which has a hardened steel core.

So, AP ammo has a steel core, but not all steel core ammo is AP.

AP penetrates not only because of the hardness of the core, but because the bullet stops on the armor plate, and its energy is converted to heat, which melts a hole in the plate, allowing the core to penetrate the partly molten steel. An ordinary bullet will cause the melting, but there will be nothing left for penetration.

Jim