Which is more important in ballistics?

[imthduke]

In a defensive rd for a handgun which is more important to consider....muzzle velocity or muzzle energy?

[DefensiveCarry.com]

[suntzu]

[481]

Momentum is the answer the question.


Excerpt from Bullet Penetration by Duncan MacPherson:

“. . . every now and then someone wants to analyze or think about a problem involving energy, and when they attempt to do this without really understanding energy or other thermodynamic concepts the result is unfortunate. One such problem is the analysis of any of the various aspects of terminal ballistics; some individuals with inadequate technical training and experience have unwisely and unproductively attempted to use energy concepts in the analysis of bullet impact and penetration in soft tissue. (Many others have simply assumed that energy is the dominant effect in Wound Trauma Incapacitation; this assumption is even more simplistic than the attempt to actually analyze the dynamics problem with energy relationships, and is no more successful).

Any attempt to derive the effect of bullet impact in tissue using energy relationships is ill advised and wrong because the problem cannot be analyzed that way and only someone without the requisite technical background would try. Many individuals who have not had technical training have nonetheless heard of Newton’s laws of motion, but most of them aren’t really familiar with these laws and would be surprised to learn Newton’s laws describe forces and momentum transfer, not energy relationships. The dynamic variable that is conserved in collisions is momentum; kinetic energy is not only not conserved in real collisions, but is transferred into thermal energy in a way that usually cannot be practically modeled. The energy in collisions can be traced, but usually only by solving the dynamics by other means and then determining the energy flow.

Understanding energy and how it relates to bullet terminal ballistics is useful even though energy is not a useful parameter in most small arms ballistics work.”

[Mike1956]

I think caliber is the most important thing.

[PEF]

Velenrgy.

[FLArmadillo]

I think caliber is the most important thing.

Well I think capacity is the most important thing...

But seriously, the FBI says that the bigger and deeper the permanent hole, the more effective. They completely denounce the effect of more or less muzzle energy.

[Brad426]

Well I think capacity is the most important thing...

But seriously, the FBI says that the bigger and deeper the permanent hole, the more effective. They completely denounce the effect of more or less muzzle energy.

Caliber AND capacity... two great tastes that taste great together.

[Mike1956]

Well I think capacity is the most important thing...

But seriously, the FBI says that the bigger and deeper the permanent hole, the more effective. They completely denounce the effect of more or less muzzle energy.

I didn't say which caliber. In my case, it is the one which affords the most rounds on a practical platform.

[FLArmadillo]

I didn't say which caliber. In my case, it is the one which affords the most rounds on a practical platform.

Then in that case, I prefer 50AE in subcompact handguns.

But really, I agree with you.

[lyodbraun]

Shot placement,.....
Shot placement

Shot placement

Sent from my DROID RAZR using Tapatalk 2

[Hoganbeg]

In a defensive rd for a handgun which is more important to consider....muzzle velocity or muzzle energy?

The answer would change according to one's purpose, but you have specified defensive use.
Consider the equation for kinetic energy:

Kinetic Energy.png

The only factors we need concern ourselves with are the variables mass (m) and velocity (v) because the others are constants.
Since the value of velocity is squared, it has the greater effect on the results of the equation. In fact, literally exponentially greater.

One other thing; if the bullet were at rest, it would have zero kinetic energy. So, one can now see that velocity dictates the energy.
Therefore, within the context of the question the answer must be velocity.

However, I'm not at all certain that is what you want to know, and if you'll excuse me, I think my popcorn is ready.

[bmcgilvray]

Terminal ballistics, properly applied.

This means good hits.

[HotGuns]

Energy is what cause one to expire, not velocity.

[msgt/ret]

Shot placement + impact energy = threat stopped.

[Mike1956]

The answer would change according to one's purpose, but you have specified defensive use.
Consider the equation for kinetic energy:

Kinetic Energy.png

The only factors we need concern ourselves with are the variables mass (m) and velocity (v) because the others are constants.
Since the value of velocity is squared, it has the greater effect on the results of the equation. In fact, literally exponentially greater.

One other thing; if the bullet were at rest, it would have zero kinetic energy. So, one can now see that velocity dictates the energy.
Therefore, within the context of the question the answer must be velocity.

However, I'm not at all certain that is what you want to know, and if you'll excuse me, I think my popcorn is ready.

There, at last, conclusive proof that my caliber is the one to carry.