Another way to help decide which cartridge to use.

[DDB TX]

Hello all, I am a very infrequent poster but I do read these forums a lot.

I see many posts about choosing "the right" cartridge. Most of the evaluations grade cartridges based upon recoil vs. velocity, and sometimes recoil vs. energy. You see a lot of statements to the effect that 300 WM is always better than 30-06, or 308Win; and you see these in every caliber that has multiple cartridge choices. But in the field, a 30-06, placed closer to the target, hits harder than a 300 WM, placed farther from the target, firing the same bullet.

I'd like to offer a different way of comparing cartridges. It is not meant to be the end-all method for choosing a cartridge, but provides a different way of looking at the plethora of cartridges out there.

In the Army we used to talk about "setback" - that is, distance from the target. A 5.56 NATO does not have as much potential effective setback as a 7.62x54, for example.

Also, many outdoors writers have spoken of a minimum impact energy for various game, measured in ft-lbs of energy at impact. I have seen the minimum ft-lbs for elk quoted as 2000 ft-lbs. I will use that figure to determine a maximum engagement range.

I'll also use the "energy at range" numbers Hornady publishes for their ammo offerings, not because they are accurate (though they are usually pretty close), but because the data came from tests done by the same people with the same equipment and methodolgy, same barrel lengths, at similar temperatures and barometric pressures, and so will show relative numbers across all the tested cartridges. Of course, your actual numbers will vary from manufacturer's numbers.

The same bullet, fired from different cartridges, will have different setbacks to exceed this 2000 ft-lbs minimum energy. For example, using Hornady's numbers from their website, a 300 Win Mag shooting Hornady's 200 grain ELD-X cartridge will carry 2000 ft-lbs of energy to about 510 yards; Hornady's 30-06 in their 178 grain ELD-X carries 2000 ft-lbs to just past 300 yards. So going from a 30-06 to a 300 WM, shooting a very similar bullet, allows you almost 200 yards more setback to achieve the same impact energy with the same bullet. In other words, in this case, you have to be 190 yards closer with the 30-06 to achieve the same energy on target; and your max ethical range is 190 yards less with the 30-06, using the same bullet.

And of course sectional density plays a great part in killing effectively, so I have tried to go with the heaviest weight / highest sectional density bullets offered, and I left out the lighter deer and varmint loads.

Also, I am not suggesting that any particular bullet is wise for taking elk, I am just using the popular energy figure for an elk as a marker for comparison.

So here are some comparisons, by caliber, taken from the Hornady website. Note the ELD-X bullets are designed for long range hunting. I was surprised at how close many of these cartridges were to each other.

Max range while retaining at least 2000 ft-lbs of energy:

.257 cal. 117 grain SST
25-06 : 125 yds
.257 Rob +P: 90 yds

.257 cal. 110 gr. ELD-X
257 Weatherby: 175yds
25-06 Rem: 130 yds

6.5 mm 143 grain ELD-X
6.5 Creedmoor: 110 yards
6.5x55 Swede: 120 yards
6.5 PRC : 300 yards

.277 cal 145 gr. ELD-X
270 Win : 300 yds
270 WSM : 340 yds

.277 cal 130 gr. GMX (copper)
270 Win: 205 yds
270 WSM: 270 yds

.284 cal. 150 gr. ELD-X
7mm-08: 200 yds
280 Rem.: 300 yds

.284 cal. 150 gr. GMX (copper)
7mm WSM: 310 yds
7mm Rem Mag: 290 yds

.284 cal. 162 gr. ELD-X
280 AI: 300 yds
7mm WSM: 430 yds
7mm Rem. Mag: 400 yds
7mm STW: 480 yds
28 Nosler: 575 yds

.308 cal. 165 gr. Interbond Superformance
.308 Win: 250 yds
30-06 : 310 yds

.308 cal. 165 gr. GMX (copper) superformance
308 Win. : 210 yds
30-06 : 300 yds
300 RCM : 380 yds
300 WSM: 420 yds
300 WM : 440 yds

.308 cal. 178 gr. ELD-X
308 Win : 210 yds
30-06: 310 yds
300 RCM: 390 yds

.308 cal. 180 gr. Interbond Superformance
30-06: 310 yds
300 WM: 450 yds

.308 cal. 180 gr. GMX (copper) superformance
30-06: 330 yds
300 WSM : 380 yds (not superformance)
300 WM : 450 yds

.308 cal. 200 gr. ELD-X
300 WSM: 475 yds
300 WM: 510 yds
300 Wby: 550 yds

.308 cal. 212 grain ELD-X
300 PRC: 600+ yds

.308 cal. 220 grain ELD-X
300 RUM: 625 yds

.338 cal. 200 gr. SST
338 WM: 475 yds
338 RCM: 425 yds

.338 cal. 225 gr. SST
338 WM: 510 yds
338 RCM: 450 yds

.338 cal. 230 gr. ELD-X
338 WM: 580 yds

 

[BoomFlop]

To summarize ... a Magnum Rifle is not needed, just get closer.

My longest shot is 294 yards, however, this is a long range hunting forum with some incredible shots.

Buckle up buddy, this could get interesting. LOL

 

[lancetkenyon]

Maybe posting the MV might help on your stats for your opinions. And shooting conditions. I am skeptical some of those numbers at most elk hunting elevations are accurate. Maybe add some heavies to the 7mm specs. Like 168, 175, 180, 184, 195s. Or a 6.5 150/160 SMK/Matrix or .308 230 Hybrid?

I am not saying I agree or disagree, but you need more specifics in your data.

 

[DDB TX]

Maybe posting the MV might help on your stats for your opinions. And shooting conditions. I am skeptical some of those numbers at most elk hunting elevations are accurate. Maybe add some heavies to the 7mm specs. Like 168, 175, 180, 184, 195s. Or a 6.5 150/160 SMK/Matrix or .308 230 Hybrid?

I am not saying I agree or disagree, but you need more specifics in your data.

Unfortunately these were all the choices available on Hornady's website. If yall want to add some MVs and weight/caliber and BCs I can run them thru the ballistic calculator to add them to this data. For example, I could run a 195 gr. 7mm with a BC of say 700 at 3000 fps and that would cross the 2000 ft-lb mark just under 700 meters out, at sea level, 59 degrees, 78% humidity. I actually enjoy this kind of geeky stuff (my first foray into reloadingtook 6 months before actually shooting, because I was learning Quickload and inputting a new wildcat cartridge, later called the 30-25 WSSM, and wanted to get it right)

So give me some numbers and I will cheerfully crunch them!

 

[DDB TX]

Maybe posting the MV might help on your stats for your opinions. And shooting conditions. I am skeptical some of those numbers at most elk hunting elevations are accurate. Maybe add some heavies to the 7mm specs. Like 168, 175, 180, 184, 195s. Or a 6.5 150/160 SMK/Matrix or .308 230 Hybrid?

I am not saying I agree or disagree, but you need more specifics in your data.

Also, Lance, please understand that this was not meant to give ACTUAL numbers, but rather COMPARATIVE numbers. The actual numbers will be different based upon a huge number of other factors like altitude, barrel length, barrel age and such. That is the advantage of using the Hornady database, it was all produced in the same place by the same guys using the same equipment. Not randomly collected from a bunch of different people off the internet or whatever.

This gives you the ability to say, for example, "I want to shoot no farther than 450 yards at elk", and then see what your calibers of choice do, roughly speaking, at that max range.

I'd also note that a lot of elk have been killed by bullets plowing along with less than 2000 ft-lbs of energy; certain 105 grain 700 yard 243 videos spring to mind. At 700 yards a 105 grain 243 bullet that left the barrel at 3000 fps is packing a tiny 477 ft-lbs. but it can one-shot an elk if placed right.

But this is an ethical long range hunting site, and I believe this information - the relative power packed by cartridges at range - is good to know for an ethical hunter.

 

[WildBillG]

This is kind of how I used to try and pick a cartridge for a given job. Glad you put this out there for us to think about.

 

[Canhunter35]

I like the comparison, personally I would use a min velocity over energy to determine set back. But it's good food for thought

 

[DDB TX]

I like the comparison, personally I would use a min velocity over energy to determine set back. But it's good food for thought

Canhunter35, the reason I like the energy number instead of a minimum velocity is that it gives a rough comparison between different bullet weights, calibers, and cartridges as well. The minimum velocity on , say, a 180 grain .308 caliber bullet for taking a given type critter will be different from the minimum velocity for any other caliber, or even any other .308 caliber bullet. That gets confusing, to me at least. But to be able to say, this .250 or 6.5 or .277 or .284 or .308 or .338 bullet, of this weight and BC, carried this much energy at this range, seems to me to be a way of comparing outcomes across calibers and weights.

It is not perfect of course, which takes us back to the old arguments of "knockdown power" vs. "hydrostatic shock", et cetera. I am not going to go there, as there is no "right" answer. Heck at the beginning of the 1900s,the 250-3000 was used on elephants, lions, etc, with an 85 grain bullet just barely going 3000 fps, and was thought to be the Wonder Bullet of the New Age! All 1700 ft-lbs at the muzzle of it!

Just trying to create a gauge to measure bullets and cartridges against each other, in a general, rough way.

 

[Canhunter35]

Canhunter35, the reason I like the energy number instead of a minimum velocity is that it gives a rough comparison between different bullet weights, calibers, and cartridges as well. The minimum velocity on , say, a 180 grain .308 caliber bullet for taking a given type critter will be different from the minimum velocity for any other caliber, or even any other .308 caliber bullet. That gets confusing, to me at least. But to be able to say, this .250 or 6.5 or .277 or .284 or .308 or .338 bullet, of this weight and BC, carried this much energy at this range, seems to me to be a way of comparing outcomes across calibers and weights.

It is not perfect of course, which takes us back to the old arguments of "knockdown power" vs. "hydrostatic shock", et cetera. I am not going to go there, as there is no "right" answer. Heck at the beginning of the 1900s,the 250-3000 was used on elephants, lions, etc, with an 85 grain bullet just barely going 3000 fps, and was thought to be the Wonder Bullet of the New Age! All 1700 ft-lbs at the muzzle of it!

Just trying to create a gauge to measure bullets and cartridges against each other, in a general, rough way.

It for sure works to compare across calibers but will always favour the heavier bullet, even when lobbed slowly.

 

[DDB TX]

Canhunter, I am not sure that heavier bullets are favored over faster bullets by energy comparisons, I think velocity is much more important.
This is from the Wikipedia article on "muzzle energy" :
"Although both mass and velocity contribute to the muzzle energy, the muzzle energy is proportional to the mass while proportional to the square of the velocity. The velocity of the bullet is a more important determinant of muzzle energy. For a constant velocity, if the mass is doubled, the energy is doubled; however, for a constant mass, if the velocity is doubled, the muzzle energy increases four times."

And this is why fast, relatively light but heavy for caliber 26 and 28 caliber rounds can compete with slower, heavier 30 and 338 caliber rounds in the big game field. Sectional density is very important too, for deeper penetration on big game and for energy retention at long range.

For example, a 150 grain .264 caliber bullet going 3000 fps at the muzzle will have the same muzzle energy as a 150 grain .338 caliber bullet going 3000 fps at the muzzle; but downrange, the .264 will always have more energy at a given distance because of its higher sectional density.

 

[cohunt]

I use velocity and bullet construction for my initial deciding factors---

how can you say that it takes a minimum of 2000 ft/lbs to kill an elk? they can be killed with archery by "cutting"--they can be killed with handguns with expanding bullets or non-expanding flat face penetrating bullets, or killed with high power rifles with penetrating, expanding/mushrooming, or "explosive" bullets--each would be a different scenario and would require a different "energy" number for minimum.

bullet construction wood be the first criteria --if you are shooting an expanding bullet make sure it will expand and work at your intended hunting distance --check the specs of the bullet, what is it's low expansion threshold ? (some rate this with velocity, others with energy)---fast expanding and explosive bullets are best shot at vitals-- bonded or mono type penetrating bullets can be used on vitals or bone--the main deciding factor or "set back" for me would be the bullet construction and velocity it is at the target, not some arbitrary "energy" number someone pulls out of a hat

after bullet construction/design and velocity--next comes accuracy, you gotta be able to hit what you are shooting at, this could be a limitation of the gun or the shooter or environmental conditions --- "perfect practice makes perfect"

 

[lancetkenyon]

Canhunter, I am not sure that heavier bullets are favored over faster bullets by energy comparisons, I think velocity is much more important.
This is from the Wikipedia article on "muzzle energy" :
"Although both mass and velocity contribute to the muzzle energy, the muzzle energy is proportional to the mass while proportional to the square of the velocity. The velocity of the bullet is a more important determinant of muzzle energy. For a constant velocity, if the mass is doubled, the energy is doubled; however, for a constant mass, if the velocity is doubled, the muzzle energy increases four times."

And this is why fast, relatively light but heavy for caliber 26 and 28 caliber rounds can compete with slower, heavier 30 and 338 caliber rounds in the big game field. Sectional density is very important too, for deeper penetration on big game and for energy retention at long range.

For example, a 150 grain .264 caliber bullet going 3000 fps at the muzzle will have the same muzzle energy as a 150 grain .338 caliber bullet going 3000 fps at the muzzle; but downrange, the .264 will always have more energy at a given distance because of its higher sectional density.

Sectional density has nothing to do with downrange remaining velocity on target. BC does.

 

[DDB TX]

Cohunt, please re-read my original post. Although 2000 ft-lbs of energy is a standard many people use as the minimum ethical impact for a standard rifle bullet (not a bow or pistol or spear or whatever) on elk, I picked it not because I believe it is "correct" but because it gives us a standard to compare various cartridges and bullets' impact at long range. I could have just as easily used 1000 ft-lbs, (which many say is the minimum ethical impact energy for whitetails) except that it would have required a lot more work since the Hornady charts only went to 500 yards, so I would have had to generate the data for each cartridge/bullet combo myself. I am NOT trying to dictate ethical ranges for your cartridge and bullet, I am just trying to demonstrate the relative downrange energy of a number of cartridges. It is a new way of looking at things for me, and pretty interesting; for example I just compared the 2000 ft-lb threshold between a 180 grain .308 Partition and a 180 grain .308 Accubond Long Range; leaving the muzzle at the same speed, the ABLR's 2000 ft-lb threshold is 150 yards farther out than the Partition's! From the same rifle!

 

[DDB TX]

Sectional density has nothing to do with downrange remaining velocity on target. BC does.

High BC means high SD....