Home Forums Hunting & Shooting Hunting Rifles Speed vs Energy?

Beautiful animal! My go to load for the UL has always been 41 grains of 4150. Never put it on the chrono, but I'd be surprised if I was getting mid 2500's out of it.

Ok, am I the only one here that doesn't give a [bleep] if an animal drops in its tracks? I learned from an early age how to blood trail a hit animal. I put the shot where it will kill them. If it runs it runs. I will find it. If it doesn't, great.
Each animal is its own unique circumstance. I don't shoot for a DRT result. I shoot for a DEAD result.

As for the argument about energy vs. speed, it is a stupid argument. You cannot have energy without speed. This isn't just a "physics thing", or an "equation thing". You simply cannot have energy without speed. Period. One follows the other, so saying one is more important than the other is like saying "oxygen content in the blood is more important than breathing".

I do not give a penny for DRT, either. The only way to be certain of DRT kills every single time is to have the nervous central system destroyed by a direct impact on the head or upper spinal cord and I never take this shots. A well hit animal can live for a few seconds before its cntral system dies of lack of oxygen and in those few seconds it can run a ways. And it will happen.

Of course that you need energy not just to kill but to do any kind of work!

It is not a meaningless parameter but not a meaningful parameter either. You just have to see the low energy an arrow carries, about the same as a 22 short, and how lethal it can be. And if it were the only consideration I guess it would be the same to chase a wounded grizzly with a 22-250 or a 45-70, as both carry similar muzzle energys, and it obviously is not.

To be precise, you can have energy without speed, two examples being thermal energy, from temperature, and potential energy, from distance to the ground.

You can have a lot of energy without a lot of speed. That tends to be pretty lethal if that energy is efficiently transferred to the animal.

You can also have a lot of speed with little energy, as demonstrated in extremis with near light-speed neutrinos. 100 trillion zip through your body every second, yet you suffer no ill effects because they don't transfer energy to your body. If they did so efficiently, you would be vaporized and the molecules and atoms comprising your body would be destroyed in an instant.

It isn't speed that kills, it is the work done destroying vital function as a bullet's energy is transferred to an animal.

I have hunted places where I didn't care about DRT. Kodiak comes to mind. If a deer does a 60 yard death dash there, you probably won't even lose sight of it. DRT matters to me in many of the areas I hunt. You really can't appreciate how thick the stuff is until you try to pick your way through it. Doing so at night with any degree of effectiveness is simply not going to happen. I'll enter this photo into evidence. If I don't DRT a deer, it is going to run into this stuff.

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Bear /Jennings archery years ago came out with the Carbon Extreme bow and the selling slogan for that bow was " Speed Kills". My first thought was speed sells!, and I think that still holds true today. It doesn't matter how fast the projectile is traveling if it misses the mark. A well placed bullet or arrow in the kill zone kills so shot placement (accuracy) is no doubt the most important to me. Next would be a bullet designed to handle the animal that you're hunting no matter how light or heavy. Speed would come in last place to me. As for DRT, it's nice when the animal drops like the ground was snatched out from under it but it doesn't always work that way, some run and some don't, but dead is dead as long as the animal is recovered. All this of course is just my opinion and you know what they say about opinions .... everybody has one.

Speed VS energy for DRT? The question is phrased poorly and neither is a great predictor of results on game.
Velocity VS half the bullets weight x velocity squared?

High shoulder shots have been the most effective way to find the "off switch" for me but I've not seen a good formula for DRT yet.

Good luck!

Yep.

None of them are dead without shot placement.

I'll take Speed because you CAN'T have a flat trajectory w/o it.

I've had DRT (Drop Right There) with.....

54 Cal Muzldrs - **SLOWEST

44 RM handgun

243-6mm - all 100 gr bullets.

6.5X55 - 140 sp

270 Win 130s

284 Win 139

7 RM 139 - **FASTEST

308 Win 150

30-06 150 & 165

300 W M 180

8mm RM 200

358 Win 180

35 Whelen 200

*** I've ALSO had death runs WITH ALL of em too.***

There is NO recipe per Speed VS Energy

IF you want DRT (drop right there) every time --- CNS is the answer. Hi Shoulder, Neck, Brain !
The brain is the SMALLEST target -- Can be messy !


Jerry

It's a lot like the guys on car/truck forums who'll argue about torque vs horsepower, while refusing to understand that they're directly related by time. Or the guys on hunting forums who'll argue that momentum matters but energy doesn't, again not understanding that those are directly related by time.

I do agree with this 100% though. That looks just like parts of our Mississippi woods; I've had to drag deer out of that stuff and definitely prefer not to if possible. When hunting in those areas I prefer to use a shot that drops them in place, rather than a traditional heart/lung/ribs shot.

I don’t think it is a question of one mattering and the other not, but which one is more linearly correlated with “killing power”. Assuming proper placement, the next most important factor is the bullet reaching the vitals, which requires exceeding a momentum threshold, and the next most important is that the bullet expands, which requires exceeding a velocity threshold. Energy is necessary for both of those requirements, but is not linear with either, and is an unreliable predictor of “killing power”.

Both are poor predictors by themselves because:

a) Speed alone cannot kill at all - it takes energy transfer to destroy vital function. Without more knowledge about the projectile, speed alone doesn't provide enough information.
b) energy alone also doesn't provide enough information - it only determines destructive potential. Without knowing how efficiently that energy will be transferred to the target, and where that transfer will occur (vitals or knee, etc.) accurate prediction of results is impossible.

This has been beat to death so much it's barely worth a response, and your comments really are a lot like the guys arguing that torque is important and horsepower doesn't mean much.

Momentum means almost nothing in relation to killing animals. Whatever "momentum threshold" you want to make up varies hugely with bullet and target construction; it's not a measure of how well a bullet can kill or how deeply it can penetrate.

Anyone still trying to argue about energy as a measure of killing power (or not) still doesn't understand it. Same as how horsepower is not a measure of how fast a car is. It's a measure of the potential to do work, that is all, don't read any more into it. The rest is up to bullet construction, shot placement, animal physiology, and other things that vary with every load used and every animal shot.

You completely misunderstand my comments, if that's what you think. Perhaps you missed my earlier posts in this thread. The concepts encompassed by Newtonian physics were established several hundred years ago and are really not up for debate, and I think if you re-read my earlier posts you'll find that you and I are really saying the same thing. I'm just pointing out that the way that many people have used the bullet's kinetic energy as a predictor of killing power is largely baseless due to the number of variables that change with each shot.

Of course the momentum threshold varies by bullet construction and target material, but the point is that there is a certain amount of momentum required for any given shot to ensure the bullet is able to penetrate to the destination (vitals). And yes, a bullet's momentum is very closely related to its ability to penetrate. If you had read my previous comments about energy and how it relates to work, you'd understand my position on the matter, and you'd know that I'm not arguing with anybody. Bullet construction matters, and the velocity necessary to initiate expansion is a function of bullet construction.

[bleep] it, I'll also say that little bullets going FAST and twisted faster, make a far greater impression on medium sized (read deer) size critters.

I guess somethings have to be SPELLED out for the Elementary!




From the above list of Calibers or Cartridges the Range is From Slow--------to Fast.
With the variety of bullet WEIGHTS -> the E figures are ALL OVER the map.

Big & Slow have produced DRT and also Death Runs.
Light & Fast have produced DRT and also Death Runs.

There is NO combination of 'those' that will consistently produce DRT.

I'll repeat:

If you want DRT, every time, it's CNS that will DROP them !

THAT is why I want SPEED, it makes hitting the target easier at longer range.


Some folks are as STUPID as....
Shiff, Peolosi, Nadler, Shumer, & Piddler > COMBINED.


Jerry

Not really, unless you're assuming a non-expanding solid in low velocity rounds. If a rifle bullet does less work (damage) along the way because of bullet design, it'll penetrate deeper with the same amount of momentum. If you increase the bullet weight (increase momentum) for the same design, it might penetrate deeper, but if you increase the velocity (also increasing momentum) it'll often penetrate less while doing more peripheral damage.

The momentum thing really is a useless value to contemplate; it doesn't tell us much about what an expanding high velocity rifle bullet can do on impact. Some guys really subscribe to momentum as a meaningful number, with made up stuff like TKO values and whatnot, but it's of very limited value unless you're trying to compare very similar bullet designs at similar speeds, in which case you're really comparing bullet weight anyway, not momentum.

Not exactly. Much of what you said is true, but consider the case of a given bullet design assuming fixed bullet mass and limited expansion, an increase in velocity typically results in deeper penetration. Monolithic bullets are a good example of this. I'm not really interested in TKO values, etc, and am approaching the question from the perspective of a Physicist.

The only reason I bring up momentum at all, and the case in which its role can readily be seen, is when encountering hard barriers such as thick bone. Again assuming that the bullet expands fully and then continues penetrating with no further expansion or fragmentation, if the bullet strikes large bone with insufficient momentum to break through the barrier, it'll be stopped against the bone. Assuming equal mass and uncompromising structural integrity, the bullet with more velocity (momentum) is more likely to penetrate the barrier. Of course bullet density and integrity come into play, and while momentum is not the be-all, end-all by any means, it does have a role to play.

The bottom line is, as long as the bullet has enough velocity to expand and enough momentum to penetrate any hard barriers it may contact, it'll kill if placed on a path to the vitals.