Does Energy have the potential to affect terminal performance?

[Lou270]

So if a bullet has a lot of energy, let's say 1K fpe, but inadequate velocity, does it just slug through with no expansion?

I'm thinking of the 178 grain ELD-X out of 308. It dips below 1800 FPS at 450 yards for my load, but stays above 1K fpe till 600 yards.

So I guess 450 yards is my cap because that's the 1800 FPS threshold. I guess anything beyond that is a non expandable projectile with a lot of energy.

Yes - you need to be within the velocity envelope the bullet is designed to deform in the target/media it was intended for.

Lou

 

[wyosam]

I do not disagree with anything you have said.

I have a follow up question. (I honestly don’t have any experience with the Barnes bullet on game) In your Barnes example where did the excess energy go? And how do we know that the excess energy did not create a larger wound diameter (by means of tearing) from the pedals cutting the material that is going to be stretched more from the increased in temporary cavity size? This is my understanding of the Barnes bullet construction so please correct me if I am wrong.

If I understand you correctly you and can take the example farther if we can find a lighter weight bullet with a a softer construction and less impact velocity than the 77 gr TMK. We should be able to do the same thing as the 77 gr TMK in a 223. So keeping it to .224 bullets could we push a 40 gr v-max at less velocity/ whatever velocity and get the same or nearly the same results. Do I understand that correctly?

All that extra energy went the same place it did with the first shot- out the other side. The only way to know how much “energy” was transferred to the animal, is to know the weight of projectile that exited AND its velocity on exit. I like two holes in animals, and even as what most on this site would refer to as a Fudd I decided energy (specifically energy minimums at the time) didn’t make any sense about 30 years ago. For the above reason. The more I’ve learned over the years, energy has meant even less. Bullet design, impact velocity (being sufficient for bullet design), and shot placement matter.


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[Macintosh]

Think of it this way. Energy does the work. Velocity, bullet construction, material density affect rate of energy transfer. Rate of energy transfer does the wounding. The bigger the energy the bigger the amount of work that can be done. The faster the transfer the wider and shallower the damage. Bullet construction for different purposes is generally done to control the rate of energy transfer for some purpose

Lou

In all things I have dealt with involving FORCE (ie energy applied dynamically) TIME is a major component of the equation. In many cases, when comparing two events, the total amount of energy applied is equal or very similar, but the force applied faster (ie over less time) results in exponentially higher PEAK FORCE. It is shown as a curve on an X/Y graph—energy on the vertical axis, time on the horizontal. the amount of energy is the total area below the force curve, but when that energy is applied faster the PEAK force applied is higher. I think this distinction between force versus peak force is what is in play here, at least to a large degree. It’s the equivalent of stopping a car. 60 to zero requires the same total amount of force, but we all know what happens if we brake gently versus slam the brakes on suddenly.
Then, with fragmenting bullets, we also have the additional component of secondary mechanical trauma applied to tissue while under tension that amplifies wounding, which I dont believe would be predicted by energy transfer alone.

 

[Lou270]

So if a bullet has a lot of energy, let's say 1K fpe, but inadequate velocity, does it just slug through with no expansion?

I'm thinking of the 178 grain ELD-X out of 308. It dips below 1800 FPS at 450 yards for my load, but stays above 1K fpe till 600 yards.

So I guess 450 yards is my cap because that's the 1800 FPS threshold. I guess anything beyond that is a non expandable projectile with a lot of energy.

In all things I have dealt with involving FORCE (ie energy applied dynamically) TIME is a major component of the equation. In many cases, when comparing two events, the total amount of energy applied is equal or very similar, but the force applied faster (ie over less time) results in exponentially higher PEAK FORCE. It is shown as a curve on an X/Y graph—energy on the vertical axis, time on the horizontal. the amount of energy is the total area below the force curve, but when that energy is applied faster the PEAK force applied is higher. I think this distinction between force versus peak force is what is in play here, at least to a large degree. It’s the equivalent of stopping a car. 60 to zero requires the same total amount of force, but we all know what happens if we brake gently versus slam the brakes on suddenly.
Then, with fragmenting bullets, we also have the additional component of secondary mechanical trauma applied to tissue while under tension that amplifies wounding, which I dont believe would be predicted by energy transfer alone.

Yep. It all plays together velocity, energy, bullet construction. Saying one is more or less important is incorrect. In the case you describe, the “stretching” is caused by energy transfer. The max diameter will be close where max force is applied in your curve.

Lou

 

[FCCDerek]

Energy is a derived number based on speed and mass. It really doesn't matter when it comes to the killing effectiveness of the chosen round. The factors that matter are bullet selection, placement, and ensuring impact inside of its optimal velocity window.