Picking the RIGHT hunting caliber/cartridge for the job. By the numbers

[packgoatguy]

Im sure variations of this topic have been beat to death... however I thought I would share the approach I took in picking a cartridge that will do the job on the game I intend to hunt.

Over the years, ive found various references to "rules of thumb" or even mathematical formulas to quantify and compare a bullet's ability to bring down a game animal quickly and humanely.

I decided I wanted to know the threshold for
1) what would give me ENOUGH bullet, without being overkill (wasting meat, too much recoil, etc)
2) kill as quickly as possible, and if necessary leave as much blood trail as necessary.
3) manageable recoil
4) High BC/wind bucking bullet options
4) and other factors including barrel life, factory ammo availability, etc.

Among the various rules of thumb, the 3 I found most impactful were:
1. energy on target ( ie, 1200 foot pounds for deer sized game and 1500 foot pounds minimum for elk or bigger game)
2. Velocity (1600 fps for minimum expansion velocity for many modern bullets, 2000-2200 fps for "hydrostatic shock effect")
3. KPS (Killing Power Score) to quantify bullet shape, diameter, sectional density, and penetrating power (ie a 12-20 KPS for deer sized game, 25-30 KPS for small elk sized game, 35+ KPS for big elk, moose, and up) Killing Power score is calculated as: energy (at the target yardage) x sectional density of the bullet x frontal area of the bullet.
E x SD x A = KPS...

But, instead of picking one or the other... I thought; why not use all three? So, I made a spreadsheet... I can share if you PM me.
My criteria was a cartridge that could take "big" elk at up to 600 yards. It needed to have
1) a minimum of 2000fps of retained velocity by the time it reached the target (with the advantage going to rounds that still were going 2200fps at the max yardage)
2) a minimum of 1500 foot pounds of energy at the target
3) a KPS score of 35 or more

Of course cartridge options like the 338LM or 300RUM would more than fit the bill... but I wanted to know the minimum.

At least for the 4000-8000ft of elevation where I typically hunt and shoot, the numbers favored the low end 30 cal magnums as a minimum threshold; ie 300 Win Magnum or 300 WSM. With pretty much any bullet choice, even out of shorter barrels and with low BC monolithic or bonded style bullets, the spreadsheet said I would still meet all three criteria at 600 yards.

Fast 7mm cartridges like 28 Nosler and 7WSM would also do the trick, but needed to be at the heavier end/ higher BC end of the bullet choice scale.

Considering I already have a bunch of 300 Win brass, the choice was for me was easy. With a brake on any of my 300 win rifles, even my kids can shoot them comfortably.

Basically, for me, the 300 win mag gives me everything I "need" for elk and under. Understanding that shot placement and then bullet construction are also important... if I know that my bullet is still carrying at least 2000fps, 1500ft pounds and has the killing power of a nearly a 44 mag at point blank range... then even I have always have enough velocity for bullet expansion, penetration through a rib, or even a margin of error if the shot isnt perfect.

Just for kicks and giggles, I ran the same numbers for "large deer and small elk" at 600 yards max range
1) a minimum of 2000fps at the target
2) a minimum of 1500 ft lbs
3) a KPS score of 30 or more

Dropping the KPS score to a 30KPS brought in the 280AI and the 7 Rem Mag.

For comparison with other popular cartridges: at 600 yards, my math shows
6.5 Creedmoor ELDX 2700MV,
2031fps target velocity
1310ft lbs Retained energy
21 KPS

308 WIN 178 ELDX, 2600MV;
1868 FPS velocity on target
1379 ft lbs retained energy
28 KPS

6.5PRC 143 ELDX 2960 MV
2253 FPS velocity on target
1612 ft lbs retained energy
26 KPS


For an excellent article of the KPS (killing Power Score), if you google it, you will find an editorial on the Chuck Hawks website.

For comparison:
At the muzzle,

.5 KPS
22 Mag pistol

5 KPS
9mm pistol

12 KPS :
223 rem 75g (rifle velocity)
10mm out of Glock 29

16KPS
G20 200gr Hard Cast 10mm
45 super
7mm-08 150gr at 1000 yards

20KPS
41 Mag
300blk

22kps
243 Win

24KPS
460 Rowland
6.5 Grendel

25 KPS
7mm-08 at 500 yards

37 KPS
6.5 CM (at the muzzle)

40 KPS
44 Mag 305 gr

60KPS
12 guage shotgun 1oz slug

70kps
30-06 at the muzzle

72KPS
458 socom
45/70

80 KPS
300 Win (at the muzzle)

126 KPS
500 S&W magnum 500gr

 

[PNWGATOR]

Wow. Not really sure what to say.

 

[MJB]

That's the minimum caliber?

 

[packgoatguy]

That's the minimum caliber?

For me, and for elk... I would say 300win if im assuming a max range of 600 yards. If max yardage were under 400, I could get it done with a 308.

 

[Darryle]

John Moses Browning would disagree

 

[mt100gr.]

KPS needs to be introduced to TMK!

 

[packgoatguy]

John Moses Browning would disagree

Browning would disagree that it is wise to factor in bullet energy, velocity, size, and construction when figuring if it will do the particular job intended? Or that based on my own rational and criteria that 300wm suits my needs best for elk hunting?

 

[PRC_GUY]

I enjoy your writing!

 

[762 ULTRAMAGA]

Browning would disagree that it is wise to factor in bullet energy, velocity, size, and construction when figuring if it will do the particular job intended? Or that based on my own rational and criteria that 300wm suits my needs best for elk hunting?

Wait for it..
The window lickers will be along shortly to tell you energy, caliber, and bullet weight is irrelevant.

 

[Bubblehide]

Wait for it..
The window lickers will be along shortly to tell you energy, caliber, and bullet weight is irrelevant.

But that is true, absolutely true, when you are lobbing a projectile the size of the earth at an animal.

 

[260madman]

Seriously? Chuck Hawks?

 

[Spoonbill]

Thanks for explaining your methodology, but this thread offers evidence to the contrary. Lots of dead animals using a 223.

.223 for bear, deer, elk and moose.

DON'T HAVE TIME TO READ 176 PAGES? HERE'S THE CHEAT SHEET. “Bullets matter more than headstamps.” “Spent primers offer the supreme tutorial”. I’ve read it here and elsewhere online. It got my attention. I started digging and asking questions and listened. The 77gr TMK delivered by a .223...

www.rokslide.com

 

[packgoatguy]

Thanks for explaining your methodology, but this thread offers evidence to the contrary. Lots of dead animals using a 223.

.223 for bear, deer, elk and moose.

DON'T HAVE TIME TO READ 176 PAGES? HERE'S THE CHEAT SHEET. “Bullets matter more than headstamps.” “Spent primers offer the supreme tutorial”. I’ve read it here and elsewhere online. It got my attention. I started digging and asking questions and listened. The 77gr TMK delivered by a .223...

www.rokslide.com

I hope I was not misunderstood. I was not intending to imply that anything less than a 300 win mag could not kill a deer... nothing could be further from the truth. I've taken several deer with a .223... albeit many years ago when the only rifle I owned was an old AR. Since then, between myself and my boys, using my rifles and bullets... we have taken deer with .243, 6.5cm, 308, 270win, 300win, and 28nos. Elk with 50 and 54 cal muzzleloaders, bows, 300 win, and 28 nos. All the game are dead and in the freezer just the same. However, with what I have learned about terminal ballistics, bullet performance, anecdotal evidence from other hunters, and the quickness of particular shots on game with various cartridges over the years... probably pushing 50 deer, elk, antelope in the past 5-10 years between my several youth age kids, nieces, brothers, my wife, etc whom I have been next to giving then range and scope data to prep for a shot at the crucial moment, giving me the opportunityto witness first hand the effects and effectiveness of different bullets and calibers.. after all this evidence, if I'm going to head for the hills and I have to pick one rifle to do it all, within my own self imposed limit of 600 yards... then I want a caliber that is going to give me least 1500ft lbs, 2000fps, and a 35kps... thus for me that is the 300 win for these and other practical considerations. There are too few variables I can control in the woods... this is one I can analyze to death in advance, and stack as much of the deck in my favor of a positive result as possible.

 

[Oneforeachofyou]

I hope I was not misunderstood. I was not intending to imply that anything less than a 300 win mag could not kill a deer... nothing could be further from the truth. I've taken several deer with a .223... albeit many years ago when the only rifle I owned was an old AR. Since then, between myself and my boys, using my rifles and bullets... we have taken deer with .243, 6.5cm, 308, 270win, 300win, and 28nos. Elk with 50 and 54 cal muzzleloaders, bows, 300 win, and 28 nos. All the game are dead and in the freezer just the same. However, with what I have learned about terminal ballistics, bullet performance, anecdotal evidence from other hunters, and the quickness of particular shots on game with various cartridges over the years... probably pushing 50 deer, elk, antelope in the past 5-10 years between my several youth age kids, nieces, brothers, my wife, etc whom I have been next to giving then range and scope data to prep for a shot at the crucial moment, giving me the opportunityto witness first hand the effects and effectiveness of different bullets and calibers.. after all this evidence, if I'm going to head for the hills and I have to pick one rifle to do it all, within my own self imposed limit of 600 yards... then I want a caliber that is going to give me least 1500ft lbs, 2000fps, and a 35kps... thus for me that is the 300 win for these and other practical considerations. There are too few variables I can control in the woods... this is one I can analyze to death in advance, and stack as much of the deck in my favor of a positive result as possible.

I think you misunderstood what the 223 thread you were linked to suggests. It isn’t evidence that 223 is good enough to kill deer- it is an argument that for most large game in NA it is the better tool compared to things like the 300 win mag you espouse in this thread.

It is also much more compelling than linking to Chuck Hawks numbers.

 

[Darryle]

Browning would disagree that it is wise to factor in bullet energy, velocity, size, and construction when figuring if it will do the particular job intended? Or that based on my own rational and criteria that 300wm suits my needs best for elk hunting?

What did they kill elk, Buffalo, grizzlies and yada yada yada with before all the science and magnum calibers?

Calibers increased in size and scope to compensate for human error. There are members and lurkers here who have had one gun, some probably a single shot, that have hunted with that same gun for their entire life and that gun would be considered anemic by other members and lurkers.

I could give the right person any number of non-magnum calibers and with the right bullet he could kill just about anything on the planet.

Case in point, buddy hunted with an Elk guide a few years ago, guy had been killing Elk with a 243 for decades at all kinds of distances.

Your science is taking into account human error. A well placed shot trumps science every time, practice with your given rifle and load, learn the anatomy of the animals you are after and take out the CNS, heart, lungs or brain and it's game over regardless of what you are using.

If we spent as much time practicing with our equipment as we did researching the means and methods, we'd have a lot less lost game, missed opportunities and a lot more meat in the freezer.

 

[Oneforeachofyou]

What did they kill elk, Buffalo, grizzlies and yada yada yada with before all the science and magnum calibers?

Calibers increased in size and scope to compensate for human error. There are members and lurkers here who have had one gun, some probably a single shot, that have hunted with that same gun for their entire life and that gun would be considered anemic by other members and lurkers.

I could give the right person any number of non-magnum calibers and with the right bullet he could kill just about anything on the planet.

Case in point, buddy hunted with an Elk guide a few years ago, guy had been killing Elk with a 243 for decades at all kinds of distances.

Your science is taking into account human error. A well placed shot trumps science every time, practice with your given rifle and load, learn the anatomy of the animals you are after and take out the CNS, heart, lungs or brain and it's game over regardless of what you are using.

If we spent as much time practicing with our equipment as we did researching the means and methods, we'd have a lot less lost game, missed opportunities and a lot more meat in the freezer.

What he is writing is not science, it is pseudo science based mostly on dogma and tradition- not data. It just dresses up like science because it sounds math-y.

The real science is new bullet technology. It is not misunderstanding the role of energy and making up some other laughable killing score.

9mm usurping 40 and 45 because of bullet technology has already happened. 223/5.56 being the better choice for large game because of bullet technology like 77g TMK is going to become popular as well. 6.5crd is a step in this direction. It will be slower than it should, because people pit science/technology against dogma and tradition.

 

[260madman]

In my fit of insomnia last night I ran some numbers with the cartridge that everyone loves to hate. 4k-8k elevation I took the middle and used 6k. If you leave out the “KPS” you get to your numbers as minimum at 600 yards.

The cartridge was 30-06 using a 168 NBT and a 178 ELDX. There’s more slippery bullets out there but these are common middle of the road bullets pre-China flu.

Im not going to say you’re wrong or poo poo your choice because you can use anything you want. Just putting this out there if someone else comes along and reads this.

@packgoatguy

 

[packgoatguy]

In my fit of insomnia last night I ran some numbers with the cartridge that everyone loves to hate. 4k-8k elevation I took the middle and used 6k. If you leave out the “KPS” you get to your numbers as minimum at 600 yards.

The cartridge was 30-06 using a 168 NBT and a 178 ELDX. There’s more slippery bullets out there but these are common middle of the road bullets pre-China flu.

Im not going to say you’re wrong or poo poo your choice because you can use anything you want. Just putting this out there if someone else comes along and reads this.

@packgoatguy

Yes, if I leave out the KPS score... (meaning a minimum of 2000fps and 1500 ft lbs of energy on target at 600 yards) then I can also get there with the 280ai, 6.5PRC, and possibly even the 270win with some loads. But for me, the KPS score of 45 (which is greater that 35) at 600 yards with the 300wm vs a KPS score of 25 at 600 yards out of the 6.5PRC is a quantifiable and significant distinction. Its not just a random number on a scale, it allows me to compare (as best as possible) other known "elk killing" cartridges, and pit my options against them, as well as identify the relative difference in bullet surface area, sectional density, and mass between my choices that a simple energy calculation does not include.

This is nothing against the 30-06. In fact, ive read that the Alaska Fish and Game recommend the 30-06 for their big game animals (moose, bear, etc). And I dont disagree... to a point. I doubt that the Alaska Fish and Game are suggesting that the 30-06 should be used at extended range as the end all be all cartridge regardless of range, and at some point on the ballistic trajectory, the velocity of a 30-06 bullet mimics a 308, then a 300blk, and so on. If my max range threshold for my own personal criteria were 500 yards instead of 600 yards, then the 30-06 would certainly be a contender (but so would a few others).

 

[Stinky Coyote]

Aside from the .223 thread here the old extreme was Bell who killed a bunch of elephants with a 6.5x54 Mannlicher and 7x57 I believe. 156-160 gr in the 6.5 and I forget what it was in the 7 but you can look it up. He killed total of 1000-1500 elephants with several cartridges but a good many fell to the 6.5 and 7 mentioned here and he was very fond of the 6.5. He figured out how to penetrate a foot of skull to get to the brain and turn out the lights. The formula that worked there was bullet construction, SD, and impact velocity. He got all those things correct. Using solids the SD remained unchanged through it's journey essentially so max penetration potential, and I believe these cartridges were launching low to mid 2000's for fps, maybe 2300-ish, so he was shooting them up close, assume 2200-ish fps impact and a bullet with a high SD that didn't change it's shape much.

At the other end of the spectrum there are guys who've tried the 700 Nitro Express with 1000 gr bullets at 3/4" diameter and SD of only .254 and launched way slower, maybe 2000 fps launch, the ft/lbs were through the roof ~10,000 ft/lbs...yet they found elephants weren't dropping, and if so they were getting knocked out and got back up and the rodeo begins. So energy was a useless measure. The higher SD and higher impact velocity of the 6.5mm 156-160's which have SD's of .32 - .328 and another couple hundred fps meant the difference. The energy from the 6.5 was peanuts.

So it's good to understand the extremes in order to figure out the goo in the middle which is where we big game hunters live.

As big game hunters we like bullets that go through squishier parts of the critters and have a changing SD as bullet disruption does more damage in the squishier parts. So we are trying to balance the same factors mentioned above, SD, construction, and impact velocity. As you add in wind fighting, max distances of 600 yards then other factors come into play such as BC, we need slipperier bullets as we push the grains of powder we burn to 'do more'. Our 21st century expectations are far greater than the 20th century.

It's a very subjective topic still when discussing terminal ballistics, not as complete as the inflight ballistics. Personally I've gravitated to a formula I prefer that is rapid expansion bullets at moderate velocities with plenty of SD and BC to do great work both in-flight and beyond the hide. I've found I need much less powder to do what I want now with modern bullet choices. Many cartridges like this will give that 18-24" penetration with rapid construction bullets and if they want to end to end elk then they run delayed controlled construction bullets that may give them 3-4' of penetration if driven hard enough. The more SD retained the deeper they go, so you'll see barnes guys for example rave about never finding a bullet and many even happy with lack of meat damage. They found a formula they like and can shoot elk up the rump running away if they must.

Many other factors one can add to the list of choices, a few others many will consider as follows;

Time of flight (TOF)
Max point blank range (MPBR)
Barrel Life
Recoil Energy
Factory Availability
Bullet Diameter (minimum preferred or legal)
Bullet Weight (minimum preferred)

Or, the OP is straight up trolling us, is it April 1st already?

 

[Wrench]

Not trying to sound arrogant or prickish....but,

Quit reading chit and go kill some stuff. If you're nervous, there's about a zillion proven combo's of case head and bullets that have worked for nearly a half century.

There's really nothing more than taking a bullet's optimal upset range and one that offers as close to as much penetration as needed and driving the damn thing home.

The internet has really made a lot of money for guys that don't deserve it.

Grab a rifle that you can stuff 5 partitions into a cantaloupe and go win your prize. If you hit the cantaloupe at 100 or 600....good, that's your end game.

Prs, benchrest, youtube....it's making people forget how to actually apply the strategies of smashing a bullet into a critter and eating it.....many are thinking about the photo op before they finish the shot.