When does a non-lead bullet become armour piercing?

[Greenmist]

Well any bullet is for military use

No they aren't, lots of bullets are not permitted for military use

 

[kenbro]

The brass is still soft enough that the rifling can grip the bullet. They penetrate very well thanks to their shape and cavitation they cause at the front of bullet.

You mate Frank is very lucky, and sounds like the buffalo died on the spot. I witnessed a cattle eating lion being shot over a cow that had been used for bait. 375 H&H bullet went through the cows horn then into the lions face. He was shooting for head on chest shot as the lion stood over the cow he was in the process of killing. We tracked that lion for two days through thick buck. It was never very far ahead, leaving lots of fresh blood, but never saw it and it never charged. It was found dead a couple of days later. All its lower jaw smashed to pieces. It was a problem lion that had taken 40 odd cattle over the course of two or three months and was taking in broad daylight out of kraals in the middle of villages and was just a matter of time before it started dining on people.

Musta bin an hungry cat!
KB.

 

[Brittany boy]

Shoot a copper hunting bullet at a steel plate target and you usually just get a round copper coloured mark on the target. They are in no ways armour piecing, nor are they designed to be so.

A copper or brass bullet are not really hard. Take one stand it upright on an anvil and give it a tap with a hammer and it will deform. Put it on its side and you can easily flatten it.

An armour piecing bullet contains a hardened steel core with a copper jacket so it can take the rifling. They are designed to penetrate armour. I have never tried one as I am not in the military so don’t know exactly how much they can penetrate. They are prohibited from sale to Section 1 FAC holders.

A lot of lead cored soft point bullets with enough impact velocity will leave a hole in piece of steel plate, even hardox plate. Have watched a few slow mo videos what seems to happen is that the impact energy immediately turns the core into a blob of red hot molten metal which then cuts through the plate almost like a cutting flame. The remaining holes have molten edges. Worst offenders are things like the 22-250 with bullets well over 3000 fps.

Yip many years ago used a girder straining post to hold a target for a 22-250. When I removed the target the damage to the girder was shocking, a very sobering experience which reinforced the requirement for a safe backstop since that day forward.

 

[dogman56]

Shotgun slugs against Kevlar - Taofledermaus who else!!

 

[NullMac]

I have some limited experience of this. I have a friend (honestly) who had a few 7.62 AP rounds “left over” from when they were legal. They were legal ??

Anyway the bold boy decides it would be a interesting to see what happens if you shoot FMJ at various thicknesses of mild steel. Not armoured.

At 100 yards 1/2” was easy as was 3/4” but on 1” plate it blew a 3/4” indent but did not fully penetrate. Out came the AP. First one, same 3/4” indent but with a fully penetrating sort of 223 size hole where the hard insert had gone through.

The third shot however the insert also went through the metal that was clamping the plate to a heavy base and was caught perfectly half way through the rear clamp. So it penetrated probably 1 1/2”

Now I though that was pretty poor considering it was mild steel not armoured plate.

The insert was still damn sharp though. He cut it out and kept it.

Let’s just say I saw the photos. Not something I would recommend, apart from the obvious illegality.

So, no the monolithic bullet is never going to be armour piercing

 

[Sea trout]

Some cross sections of armour piercing bullets.

a key function of armour piercing bullets is to penetrate at the cost of not transferring energy. Almost the exact opposite of a hunting bullet therefore there is a clear distinction between the two and I would challenge your comment that any bullet is for military use.