7.62x39mm gel test: Tula 154 gr soft point

[AndrewWiggin]

I shot this into out of spec gelatin from a 10.5" PAP earlier today. Still expanded just fine. I'll post details when I get a chance.

[Stengun]

Howdy,

I shot this into out of spec gelatin from a 10.5" PAP earlier today. Still expanded just fine. I'll post details when I get a chance.

Paul

[AndrewWiggin]

*sigh*

Crappy cell phone pics of the recovered projectile from the short barrel test:





Remember that the gelatin was out of spec. Shouldn't have much impact on how the bullet deformed but obviously the penetration figure would have been invalid if I recorded it. It was probably about 18", which, if you account for the out of spec gelatin, is roughly consistent with the other result. You'd expect a bit more penetration at lower velocity.

Velocity was 1,966 fps.

[Stengun]

Howdy,

Well, that would certainly get the job done!

Paul

[Ron3]

Would like to see a few more of these tested.

I'll never forget my simple mud-in-a-cardboard-box test of Silver Bear 140 gr JSP from a PTR91:

Fired three rounds into the open-top box from about 30 yds. Surprisingly there was no mud splatter from the top, sides, or back of the box. I wouldn't believe it if I hadn't see it but NONE of the bullets exited the box. Oh, did I tell you the box was only about six inches thick?! And you'd be safe from these .308 rounds behind it.

So I dug into the box and found nothing but tiny pieces of jacket and lead from the three rounds. They had totally fragmented into little bits without making any kind of stretch cavity effect in mud at all. Just because a bullet fragments doesn't mean it has a big "shock" or "energy dump" effect. They can fragment in favor of nothing.

But I digress. Thanks for the test!

P.S. If you want to save your steel targets from .308 I recommend Russian JSP's..

[MegademiC]

Would like to see a few more of these tested.

I'll never forget my simple mud-in-a-cardboard-box test of Silver Bear 140 gr JSP from a PTR91:

Fired three rounds into the open-top box from about 30 yds. Surprisingly there was no mud splatter from the top, sides, or back of the box. I wouldn't believe it if I hadn't see it but NONE of the bullets exited the box. Oh, did I tell you the box was only about six inches thick?! And you'd be safe from these .308 rounds behind it.

So I dug into the box and found nothing but tiny pieces of jacket and lead from the three rounds. They had totally fragmented into little bits without making any kind of stretch cavity effect in mud at all. Just because a bullet fragments doesn't mean it has a big "shock" or "energy dump" effect. They can fragment in favor of nothing.

But I digress. Thanks for the test!

P.S. If you want to save your steel targets from .308 I recommend Russian JSP's..

Mud is not a good test medium.

If the round fragments it does have to have "energy dump." The energy it takes to fragment the round is also applied to the medium. Newton's first and third laws of physics explains it.

However, this round may not penetrate enough to be a good defense round, but that's a different issue.

[Ron3]

Mud is not a good test medium.

If the round fragments it does have to have "energy dump." The energy it takes to fragment the round is also applied to the medium. Newton's first and third laws of physics explains it.

However, this round may not penetrate enough to be a good defense round, but that's a different issue.

I agree about the mud.

But I'm not sure that just because a bullet fragments it moves the material it crashed into that made it fragment.

Consider a drinking glass thrown against a cement wall. The glass fragments, the wall is not affected.

Now consider a chunck of cement thrown against a glass window. The glass breaks, the cement is not affected.

Myth Busters did a test of a frozen water bullet. If I recall, it did hardly any damage to simulated tissue, but the bullet itself was destroyed.

I'm just not convinced that when objects collide they split the energy transfered 50/50 every time.

[AndrewWiggin]

The Mythbusters ice bullet did about the same amount of damage that a lead or copper bullet of the same mass would do at that velocity. The ice bullet was very light.

The law of conservation of mass and energy means that the kinetic energy contained within the bullet is transferred completely to the target/bullet system. NONE of the energy can be lost but a significant portion can be transformed from kinetic energy to heat energy.

[MegademiC]

I agree about the mud.

But I'm not sure that just because a bullet fragments it moves the material it crashed into that made it fragment.

Consider a drinking glass thrown against a cement wall. The glass fragments, the wall is not affected.

Now consider a chunck of cement thrown against a glass window. The glass breaks, the cement is not affected.

Myth Busters did a test of a frozen water bullet. If I recall, it did hardly any damage to simulated tissue, but the bullet itself was destroyed.

I'm just not convinced that when objects collide they split the energy transfered 50/50 every time.

Apples to steak. You're examples have vastly different mass. Rock to glass, very little energy is transferred. The rock keeps moving with similar speed. Glass against cement, the glass energy is used to break it and then the remaining energy is in kinetic energy as it flies all over the place.

The 140gr bullet, while a little light, has very similar mass and energy(unless it is a really slow round), to other 308 bullets. There is a gel vid online that shows the tc of this round. It's very long and not very wide, but it penetrated deep. Depending on the consistency of the mud, it may not show tc.

All the energy goes somewhere, heat, noise, continued motion of projectile, and movement of target. Fragging keeps most energy in the target. You can't make energy disappear without creating mass, but that's some high level nuclear physics.