Minimum Velocity Clarification

[Talkyn]

Also, as far as I'm concerned, KE is an abstract measurement of energy and no one can quantify just how that translates to killing power.

All my research, experience and intuitive thought mirrors this statement exactly.

IMHO, making a hole in an animal is fatal. The bigger the hole, the better. The more vital organs you punch your hole through, the better.

I would suggest that momentum would be a better figure to refer to, but still largely useless alone. Caliber diameter, flesh toughness, whether or not you strike a bone, bullet expansion rate, bullet toughness....There are so many variables it's very hard to break down what works best for what reasons.

I'm under the impression that this forum is chock-full of reliable information that generally supports the 1800fps minimum figure in most circumstances.

If you really want to know what a given bullet will do at 1800, 1600, 1300, etc... Shoot some media like homebrew ballistics gel or wet phonebooks. I'm hoping to do some of that myself in the near future.

 

[MontanaRifleman]

IMHO, making a hole in an animal is fatal. The bigger the hole, the better. The more vital organs you punch your hole through, the better.

Exactly

I would suggest that momentum would be a better figure to refer to, but still largely useless alone. Caliber diameter, flesh toughness, whether or not you strike a bone, bullet expansion rate, bullet toughness....There are so many variables it's very hard to break down what works best for what reasons.

Bingo again and I agree that momentum is a better measurement of killing power but it too is just a mathematical number that only takes into account 2 of a dozen or more factors involved.

 

[mrb1982]

Seems like a guy has got to kinda come up with your own system or mentality, and do the best you can to apply it in an ethical matter. Seems there is probably not entirely right or wrong way. There's the guys with the 338's that won't shoot a deer over 500yds and something like that Davidson kid shooting an elk at 1376yds with a 7RM. To each their own, they all seem to work.

If there is one thing that from what I can gather out of all this conversation, is that shot placement trumps all. As far as the bullets performance, outside of a couple control factors, is on the honor system. But the key is practice, put whatever bullet you got where it belongs, and go collect your animal.

 

[Canadian Bushman]

Im not trying to be argumentative or offend anyone, but i want to clarify where my stance on projectile energy because i think im being misunderstood.

I do not disagree that there are way too many variables on defining a bullets lethality on game, to say energy alone can sum them all up. However the same statement applies to velocity.

We have yet to specify a bullet to represent this 1800 fps mark, i assumed we were all leaning toward bergers. Please correct me if we are in fact discussing another bullet.

I disagree that energy is a ball park measurment. I will agree it is technically abstract, since it is a figure of bullet weight and speed, but it is no less accurate.
Momentum cannot be any better determining factor because it describes the same quality of a projectile and is calculated in the very same manner.

M=m x v
kE=1/2m x v^2

I like to use energy because it gives me a good idea of the range i have for a particular caliber/bullet weight, and its potential to inflict damage.

Just like velocity, energy is completely dependant on bullet performance. If the bullet hits soft tissue and pin holes you just wasted whatever velocity and energy you had.

If the bullet strikes bone, you just dumped whatever velocity and energy into the body of the animal and will cause a lot of damage. Energy in my mind is an accurate description in this type of shot.

I in no way advocate the use of any one measurment to describe performance of a large variety of bullets in a large variety of animals in a large variety of situations. I think a shooter should pick a bullet to suit their own personal needs. Work to understand to external and terminal ballistics of said bullets, and apply them in a responsible manner.

On a personal note i did read a forum where eric stecker specifically stated the berger bullets opened up much more consistantly above the 1800 fps mark, and i am in no way debating this. Im simply advising to use energy to make sure you have the requirement to quickly dispatch your game. It should also be stated that berger bullets can have unpredictable results if contacting the animal too fast. I dont know a round about number but i have pin holed a good number of feral hogs with very close range shots. As well as having them grenade inside and drop them on their belly.

Thanks for hearing me out

 

[mrb1982]

You make some very good points and I agree with your judgement as far as the type of bullet you are using.

There are people like a lot of us long range shooters that are using bullets relying on expansion.

Then there are the guys that like to shoot some of those bullets like the partitioins and some of the others that swear less expansion is better and penetration is key.

You are right, there are a lot of ways to figure out the bullets capabilities, and everyone just has to do what they have confidence in and go from there.

 

[MontanaRifleman]

Im not trying to be argumentative or offend anyone, but i want to clarify where my stance on projectile energy because i think im being misunderstood.

I do not disagree that there are way too many variables on defining a bullets lethality on game, to say energy alone can sum them all up. However the same statement applies to velocity.

We have yet to specify a bullet to represent this 1800 fps mark, i assumed we were all leaning toward bergers. Please correct me if we are in fact discussing another bullet.

I disagree that energy is a ball park measurment. I will agree it is technically abstract, since it is a figure of bullet weight and speed, but it is no less accurate.
Momentum cannot be any better determining factor because it describes the same quality of a projectile and is calculated in the very same manner.

M=m x v
kE=1/2m x v^2

I like to use energy because it gives me a good idea of the range i have for a particular caliber/bullet weight, and its potential to inflict damage.

Just like velocity, energy is completely dependant on bullet performance. If the bullet hits soft tissue and pin holes you just wasted whatever velocity and energy you had.

If the bullet strikes bone, you just dumped whatever velocity and energy into the body of the animal and will cause a lot of damage. Energy in my mind is an accurate description in this type of shot.

I in no way advocate the use of any one measurment to describe performance of a large variety of bullets in a large variety of animals in a large variety of situations. I think a shooter should pick a bullet to suit their own personal needs. Work to understand to external and terminal ballistics of said bullets, and apply them in a responsible manner.

On a personal note i did read a forum where eric stecker specifically stated the berger bullets opened up much more consistantly above the 1800 fps mark, and i am in no way debating this. Im simply advising to use energy to make sure you have the requirement to quickly dispatch your game. It should also be stated that berger bullets can have unpredictable results if contacting the animal too fast. I dont know a round about number but i have pin holed a good number of feral hogs with very close range shots. As well as having them grenade inside and drop them on their belly.

Thanks for hearing me out

I want to make clear that I am not jumping on anyone and I mean no one any offense. Just trying to be objective and realistic about the facts.

OK, so if we look at the KE formula, we see that the "mass" input is reduced by half and the velocity input is squared. This obviously would not be able to predict penetration. So my question is, just how does KE translate to destructive killing power? The KE number rises exponentially with velocity implying that velocity is a much greater factor in destruction than mass. That is simply not accurate. I will agree that higher velocity lighter bullets can cause significant damage but at the same time slower and larger bullet penetrate better.

IMO, although momentum is not a perfect indicator of "destructive" force, it is a good indicator of potential "penetrating" force. I say potential because the expansion performance of the bullet will have a great affect on penetration. It takes mass and velocity equally into account.

Bottom line is that there are just too many variables and mathematical formulas that don't factor those variables in are not great indicators of potential terminal performance.

The popular KE number for killing "elk" is 1500 ftlbs. I will say that there are bullets that in some circumstances that are very capable of killing a bull elk down to 1000 ftlbs of KE. And when hunting cows, most cartridges suitable for deer are also suitable for cow elk.

Know your game, know your bullet's external and terminal ballistics and place your shot well.

 

[Canadian Bushman]

Im not sure if i agree with your reasoning but i most certainly agree with your conclusion and i think thats what the purpose of this thread was aimed at. If not we have sure drawn attention to some particular characteristics of terminal ballistics that will give others something to think about.

Montana rifleman i enjoyed the discussion, if you would like to continue in pm or another thread im always honored to hear your opinions. For the time being i wouldnt mind hearing others comments and honestly im a little tired of typing.

Thanks again ill be watching the thread.

 

[MontanaRifleman]

Im not sure if i agree with your reasoning but i most certainly agree with your conclusion and i think thats what the purpose of this thread was aimed at. If not we have sure drawn attention to some particular characteristics of terminal ballistics that will give others something to think about.

Montana rifleman i enjoyed the discussion, if you would like to continue in pm or another thread im always honored to hear your opinions. For the time being i wouldnt mind hearing others comments and honestly im a little tired of typing.

Thanks again ill be watching the thread.

My pleasure!

 

[Talkyn]

I want to point out an error in your description of the KE equation. It could be simple semantics but I feel clarity is best.

The formula posted is correct, KE = 1/2mv^2

It represents a logical fallacy to say that this is 1/2 of mass times velocity squared. When we do multiplication in a row like this, each value is multiplied together so mass isn't given only half value because velocity squared is also halved when we finish the calculation.

What I mean to say is, when using your intuition to guess at the importance of each variable in the formula, you should think of it as KE = (m x v^2)/2 so you don't mistakenly assign too little relevance to the impact of mass on the end result.

On the subject of momentum vs KE, both are simply tools that are often incorrectly used as general guidelines in killing power. In my earlier post I preferred momentum because it gives equal credence to both mass and velocity. Large caliber, poor/non-expanding bullets at low velocity are extremely lethal as proven all over Africa and right here in NA before the advent of smokeless powder. The KE figures on most of these cartridges are laughable compared faster, modern ones.

The most important thing for me is advocating that we cannot use either of these derived figures as a true measurement of killing power.

I'll give an obvious example of why this might be a bad idea. I'm picking on KE here only because I can't come up with a good example for momentum at the moment:

If we take a 22-250 Rem with a 50gr bullet launched at 3850fps we get 1645ft lbs of energy at the muzzle. This leaves 1200+ft lbs at 100 Yards, a figure I've often seen as "needed" for big mule deer.

I wish I could say I didn't have experience with what the 22-250 and such a light bullet isn't capable of on game that size, but I've had the "pleasure" of hearing a lot of stories (I work hunting retail) of lamenting hunters talking about their targets bounding off, leaving no blood trail and never being recovered. What went wrong? Not a very big hole and not very deep.

If we load up the same rifle with a 60gr Nosler Partition, the KE figures are almost exactly the same but we will see a much more favorable terminal result. I have locals that I have been unable to talk out of using their 22-250s that have at least stepped into the 55gr Fusions and 60gr Partitions and report good results from the change, even providing an exit wound in some cases. Maybe the hole is the same diameter as before, but now it's a lot deeper.
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This shouldn't really tell an intelligent hunter anything, since we all know to choose cartridges and bullets that are suitable for the game we pursue based primarily on either personal experience or the experience of the hunting community around us. We can't rely on these formulas in a vacuum. I'm sure we all know that without me saying it.

New hunter's almost always ask, "What caliber do you recommend for deer/elk/moose/bear?". Experienced hunters usually suggest some bullets along with their pet calibers, do they not?

Canadian Bushman, the way you are using KE in my mind is perfectly correct. It is obvious you have weighed all the other factors you can (suitable cartridge size, suitable bullet construction) and are using it as a comparison between loads and/or calibers. After my whole speal, I have to admit I occasionally do the same. More often however, I am looking for a personal 2000fps breakpoint to determine my maximum range. I'm not experienced at long range hunting as of yet and this number coincides with where I am comfortable with accurate shot placement.

 

[Canadian Bushman]

There are two complications when comparing momentum to energy besides the effect of velocity on the actual momentum/energy figure.

First is direction of travel.
Energy is a description of kinectic energy regardless of direction.

Momentum is a description of an objects resistance to stop in one direction.

Bullets always travel two directions regardless.
Away and down.

In terminal ballistics or any collision there are two types. Elastic and inelastic.
Elastic collisions mean it was an ideal transfer of 100% energy. And momentum is conserved whether transferred or not.

Inelastic means energy was dispersed in multiple ways and was not transferred all in one direction. Usually dispersed as heat sound and deformation of materials. Therfore momentum is inconsistant and uncaculable.

Almost every impact a bullet has with an animal is an inelastic collision. Energy is always dispersed and so in multiple directions.

In my opinion energy better suits terminal ballistics and is why it is so commonly used to describe a projectile.

 

[MontanaRifleman]

I want to point out an error in your description of the KE equation. It could be simple semantics but I feel clarity is best.

The formula posted is correct, KE = 1/2mv^2

It represents a logical fallacy to say that this is 1/2 of mass times velocity squared. When we do multiplication in a row like this, each value is multiplied together so mass isn't given only half value because velocity squared is also halved when we finish the calculation.

What I mean to say is, when using your intuition to guess at the importance of each variable in the formula, you should think of it as KE = (m x v^2)/2 so you don't mistakenly assign too little relevance to the impact of mass on the end result.

You are correct and good point. That said, velocity is still factored exponentially compared to mass in the KE equation and IMO is not a viable measurement of destruction and killing potential. It does give us a vauge relative reference of the bullet's potential but that is as far as it goes.

Let's take the 22-250 example. My 22-250 will shoot 53 Vmax bullets to 4100 fps. At he muzzle, that is almost 2000 ftlbs of KE which is 33% more energy than a lot of folks say is minimum for killing elk. At 125 yds, the KE drops to the magic 1500 ftlbs requirement for elk. I would not shoot an elk at any range with this cartridge/bullet combo. Let's load the 60 Nos Partition. Let's assume an MV of 3900. The KE numbers will be very clost to the 53 Vmax. The Partition will likely penetrate much better but do we really want to shoot a large bull elk with this combo? The small hole greatly increase the odds that the bull will run off somewhere never to be found.

Now let's look at the Nos ABLR and Berger 7mm 168. With an MV of 2600 fps out of a 7-08, they have about the same energy @ 300 yds as the 22-250 bullets do @ 25 yds. Which will be the more effective killer? At 700 yds they have a velocity of about 1870 and a KE of 1300. A well placed shot through the lungs will effectively kill a bull elk. @ 950 yds the velocity is about 1604 and the KE about 1000. The Berger will probably pencil through but the ABLR will expand and penetrate both lungs and likely exit. Although probably not a highly recommended shot, the odds are it will effectively kill a large bull and one I would choose over the 22-250 @ 25 yds.

A 210 gr hardcast flat nose 44 cal bullet fire @ 1200 fps from a 44 mag will have 650 ftlbs @ 25 yds. I would choose the 44 cal hardcast bullet with 1/3 the KE of the 22-250 bullets.

KE just doesn't cut it as a determiner of killing potential.

 

[Talkyn]

A 210 gr hardcast flat nose 44 cal bullet fire @ 1200 fps from a 44 mag will have 650 ftlbs @ 25 yds. I would choose the 44 cal hardcast bullet with 1/3 the KE of the 22-250 bullets.

KE just doesn't cut it as a determiner of killing potential.

Thanks for digging up some more figures. I was running out of time before I had to leave for work!

Bushman, what merit is the dispersion of this energy into the animal vs. the creation of a hole? If you use a bullet like a Berger that explodes inside the vitals, it is not the KE that stops the organs' functions, it is the nasty spray of shrapnel; the holes.

Montana's 210gr hard-cast sure as heck doesn't put any energy into the animal, yet it will be dispatched very quickly. Anyone that doubts this should really see it first hand. A co-worker uses his 45-70 Marlin almost exclusively with hard-cast bullets at very moderate speeds with tremendous success on moose.

We would all do well to recall that the first truly long range firearms where in calibers like the 45-70 and it's larger cousins. The trajectories are terrible, the KE figures are terrible, but the leathality is proven.

Gosh we've trailed off-topic haven't we?

Minimum velocity, in my opinion, varies greatly on the intended target and the bullet's construction. I've somewhat guessed at 2000fps for my uses in my rifle. Obviously if you are out there with a 45-whatever you will have to use a different number that you arrive at through research or experimentation.

If Berger says 1800fps, I would use 1800fps with those bullets unless I had reason to think otherwise.

 

[Canadian Bushman]

Bushman, what merit is the dispersion of this energy into the animal vs. the creation of a hole? If you use a bullet like a Berger that explodes inside the vitals, it is not the KE that stops the organs' functions, it is the nasty spray of shrapnel; the holes.

A bullet fragmenting and stopping inside an animal is indeed dumping energy. It is creating a large wound cavity, or a lot of small ones and a massive amount of surrounding tissue damage, trauma, resulting from extreme shock. This is precisely what berger advertises their bullets design is intended to do. Every animal i have shot where the berger performed as said was filled with mush. Not tissue with lots of holes in it, but mush. This is also reffered to as hydrostatic shock. Another highly debated topic that in my mind is a result of a intentionally deformed bullet dumping energy. Usually revealing itself as the damaged, blood shot, tissue surrounding the bullets entrance/exit. Hunting deer with lead buck shot is another fine example of this and a very efficient way to kill quickly.

 

[Canadian Bushman]

Thanks for digging up some more figures. I was running out of time before I had to leave for work!

Bushman, what merit is the dispersion of this energy into the animal vs. the creation of a hole? If you use a bullet like a Berger that explodes inside the vitals, it is not the KE that stops the organs' functions, it is the nasty spray of shrapnel; the holes.

Montana's 210gr hard-cast sure as heck doesn't put any energy into the animal, yet it will be dispatched very quickly. Anyone that doubts this should really see it first hand. A co-worker uses his 45-70 Marlin almost exclusively with hard-cast bullets at very moderate speeds with tremendous success on moose.

We would all do well to recall that the first truly long range firearms where in calibers like the 45-70 and it's larger cousins. The trajectories are terrible, the KE figures are terrible, but the leathality is proven.

Gosh we've trailed off-topic haven't we?

Minimum velocity, in my opinion, varies greatly on the intended target and the bullet's construction. I've somewhat guessed at 2000fps for my uses in my rifle. Obviously if you are out there with a 45-whatever you will have to use a different number that you arrive at through research or experimentation.

If Berger says 1800fps, I would use 1800fps with those bullets unless I had reason to think otherwise.

Its not always about how much energy a bullet has but how much can be transferred to the intended target.

This was the sole purpose for the creation of the slow flying 230gn 45 ACP.

Flat nosed lead bullets are wonderful for hunting because there ability to deform, and there flat nose aids in the transfer of energy as well as initiating a very stable, straight traveling expansion, that in my mind creates an ideal wound cavity as well as tissue damage . Another interesting trait of these bullets is that the recovered projectile is usually half the weight of what was fired. If it is not it either hit bone and exploded or exited the animal wasting energy. For purely hunting, a lead wadcutter will probably be close to an ideal design. However they fly like a brick. I prefer my bullets pointed.