What hits harder?

[postoak]

Has anyone figured out Taylor's formula so we can calculate other cartridges? I'd like to know, specifically, what the 9.3 x 62 figure is. Or is that what he meant by ".366"?

 

[Badboymelvin]

Apple & oranges?

The question is "What hits harder?" and the response proposes to use energy as a unit of measure "Both develop about the same muzzle energy, somewhere around 5,000 lb./ft."

This is not the direction I would go...

In the calculation of energy:
- velocity is squared;
- mass (i.e. weight in everyday language) is not;
- frontal area is not a factor included in the equation.

These are the reasons why high velocity calibers make up in energy over larger calibers shooting heavier slugs at lower speed.

Using Swift factory data for both cartridges, so that reloads variations are mostly taken out of the discussion, the .416 Rigby 400 gr has a 288 fps initial velocity advantage over the .458 500 gr. This gives the .416 a muzzle energy of 5,250 over the .458's 5,100.

View attachment 338600

Going by energy alone, the .416 400 gr hits 3% harder than the .458 Win 500 gr...

For comparison, still going by energy alone, the .458 Lott 500 gr hits 4% harder than the .416 Rigby 400 gr, and 7% harder than the .458 Win 500 gr...

I own a .458 Lott, I too in the pre-chronograph days was convinced that it outperformed the .458 Win by grand leaps and majestic bounds, but as hinted by Badboymelvin, the DATA shows otherwise. 7% additional energy is hardly worth writing home about, especially (see here under) if the price to pay for 7% higher energy is 27% more recoil...

View attachment 338612

There is a large body of experience in the hunting world going back a century that challenges the use of kinetic energy alone as an adequate measure of how "hard" a bullet "hits"...

One with considerable experience who took the pain to try to design a better answer was "Pondoro" John Taylor. He designed a formula to calculate what he called the Knock Out Value (KO value).

This table is copied from Taylor's African Rifles and Cartridges:
View attachment 338603

The table does not show the .458 Win because it did not exist at the time the book was written (1948), but since the .458 Win 500 gr load was designed to duplicate the .470 500 gr load in both velocity and energy, we can approximate an answer using the .470 500 gr data. The only .416 in existence in 1948 was the Rigby, so the .416 data is the one we are interested in.

The KO value for the .470 500 gr / .458 500 gr is 71.3
The KO value for the .416 410 gr is 57.25

Using Taylor's KO value, the .458 Win 500 gr hits 25% harder then the .416 400 gr.

Taylor's comment "suffice it to say that the final figures agree in an altogether remarkable way with the actual performance of the rifles under practical hunting conditions" are good enough for me. Personal choices of life set aside, it will be a looooong time before I challenge Taylor's expertise and experience hunting dangerous African game...

View attachment 338611

Recoil

A 10 lbs .416 Rigby rifle shooting a 400 gr bullet at 2,400 fps generates 58 ft/lbs of free recoil.

A 10 lbs .458 Win Mag rifle shooting a 500 gr bullet at 2,100 fps generates 55 ft/lbs of free recoil.

(For comparison, a 10 lbs .458 Lott rifle shooting a 500 gr bullet at 2,300 fps generates 70 ft/lbs of free recoil.)

I hope this was of interest

Hey mate,

That was an AWESOME post!
Thanks for sharing

Cheers,

Russ

 

[One Day...]

Has anyone figured out Taylor's formula so we can calculate other cartridges? I'd like to know, specifically, what the 9.3 x 62 figure is. Or is that what he meant by ".366"?

https://en.wikipedia.org/wiki/Taylor_KO_Factor

Yes, the .366 data in Taylor's table refers directly to the 9.3 Mauser (a.k.a. 9.3 x 62). Taylor's view of it was: "There is nothing spectacular about it: it's just a sound, reliable, general purpose cartridge ... There isn't really a great deal to say about it. Everybody found it so generally satisfactory that there wasn't anything to start a discussion" (p. 140 - 141).

 

[Ray B]

This doesn't answer the question but something to consider is: What does the bullet do? It inflicts damage to the animal by transferring its energy to it. In defining how hard something hits one needs to determine how the energy of the bullet was transferred. Doing this involves those various attributes of the bullet.

 

[bruce moulds]

you could say that hitting hard is about destroying the central nervous system.
this can be done by hitting the spine above a certain point or the brain itself.
next best is reduction of blood pressure.
the thing that does these things best is the hardest hitting?
taylors k.o. figure is not about killing, but knocking down for long enough to do what is necessary next.
there are many factors to consider in this subject.
for example, solids will in many situations not knock down like good softs, and are even better avoided for good results.
but in other situations, the reverse is the case.
I often suspect that there in more trouble in this day and age from too much bullet as opposed to too little.
bruce.

 

[postoak]

Weight x velocity/7000 is just momentum with a units conversion, so his formula is momentum x area?

 

[BenKK]

Really good points, Bruce. Maybe with elephants solids hit hard (beyond my experience) but with buffalo solids (whether traditional or modern design) almost never “hit hard”. Actually, I could simply say they never hit hard. They can achieve quick kills, sure, by hitting the right spot at the right time. But to be able to notice the varying degrees of being “hit hard” requires the use of traditional softs, which impart the most noticeable punch/impact/shock/shudder rather than a mere fatal zip-through (no matter how rapid).

 

[BenKK]

Mind you, I’m not saying that the zip-through is a bad thing, because it’s just fine and dandy and has merit in some situations.

 

[One Day...]

Mind you, I’m not saying that the zip-through is a bad thing, because it’s just fine and dandy and has merit in some situations.

I agree. I have learned this, using with amazing effect the .257 Wby 100 gr TTSX on plains game in Africa, from the smallest all the way to Roan.
In this case (the "zip-through") I believe that there is an additional factor at play: hydrostatic shock.
It clearly seems to require a hit velocity of at least 3,000 fps, which few cartridges accomplish at hunting ranges - hence, I suppose, why the hydrostatic shock is so decried ... because it is generally not delivered by most hunting cartridges - but when it happens it is spectacular on plains game.

This being said, this is another discussion, as indeed plains game "situations" are utterly different from knock down power as discussed in this thread

 

[ChrisG]

I see a lot of reference to Taylor's knockout formula but often people forget that his formula wasn't intended for use on anything but elephant brain shots. His formula was to estimate to potential knockout capability of a solid bullet which penetrates the head but barely misses the brain. Any other application of his formula is just speculation based on many years of gun writers misapplication.

Once an animal gets to be a certain size (in my estimation pretty much anything over 400-500lbs falls into this category), It is very difficult to overwhelm them with either energy or a "knockdown" blow from anything that is shoulder fired.

That said, a .458 does have the potential for more killing power but there probably aren't any people alive today who have killed enough animals with both to make a definitive case that one is better than the other (especially with modern bullet technology) as they are probably so close you would be hard pressed to tell any discernable difference in effect between the two.

 

[bruce moulds]

excellent post chris.
absolutely in touch with reality.
bruce.

 

[bruce moulds]

I know my 9.3x64 hits camels and donkey hard when I put a swift on the point of the shoulder facing me at a slight angle.
the whole body spasms and the head goes back with the mouth open and it is dead before it hits the ground.
the same shot with a nosler partition has nowhere near the same result.
they both technically hit as hard, but to the eye, the swift hits harder.
my 7mm stw hits way harder than my 280 with similar bullets on the same game.
plus it has the advantage of hitting bigger game harder with heavier bullets.
bruce.

 

[ChrisG]

excellent post chris.
absolutely in touch with reality.
bruce.

I am of the mentality that where the bullet goes and what it hits/breaks after impact has an overwhelmingly larger effect on the perceived "impact" to the animal than any additional 0.03" difference in bullet diameter or a peanuts mass in difference of bullet weight. I will say that the .416 is far more versatile. It shoots flatter and thus is easier to hit with once range extends beyond 100 yards on plains game or large cats (I dont know as I'd shoot any of the big 5 out past 100 yards though because I'd really want to know where my bullet was going). With a 340-350 grain bonded or monometal bullet, I wouldn't hesitate at a 250 yard shot on deer sized game if the rifle is sighted for 150. I dont know if I'd attempt that with any of the 458s except maybe the 450Rigby/460 weatherby as they certainly would shoot flat enough. However, I will never own one of those as my ability to shoot it well would be really compromised due to the ridiculousness of their recoil.

 

[Nhoro]

Taylor’s formula uses the diameter of the bullet while the size of the hole is given by Pi radius squared.So Taylor’s formula essentially uses a proportional value for the size of the hole and the energy of the bullet. It at least gives some idea of how a bullet may perform. Having thought about it, I prefer energy per mm2 as an estimate of penetration, similar but a little more scientific.

As for the notion that penetration and the power of the hit,I think the two are different and measurable.in physics, you can use a ballistic pendulum to measure how much energy a bullet transfers and therefore how hard it hits. Then penetration is how deep it penetrates. Different things and ultimately you want both.An example would be a 375 H&h vs 458 win mag. I think everyone would agree 375 will penetrate deeper and 458 will hit harder.

 

[Nhoro]

I am of the mentality that where the bullet goes and what it hits/breaks after impact has an overwhelmingly larger effect on the perceived "impact" to the animal than any additional 0.03" difference in bullet diameter or a peanuts mass in difference of bullet weight.

20 % more cross sectional area and 25% more mass and 13% more energyI would say that was significant.

 

[ChrisG]

I am of the mentality that where the bullet goes and what it hits/breaks after impact has an overwhelmingly larger effect on the perceived "impact" to the animal than any additional 0.03" difference in bullet diameter or a peanuts mass in difference of bullet weight.

20 % more cross sectional area and 25% more mass and 13% more energyI would say that was significant.

While your percentages are correct, that's like saying "drinking beer increases your chance of getting cancer by 1000%". Considering your chance is already like 0.002% you just increased it to 0.02%. So what I am saying is on an animal whose vital area is already like 150 sq.in. in area, the difference between 0.136 sq. in (.416 dia.) And 0.165 sq. in. (.458), really amounts to a hill of beans. So the .416 has occupied 0.09% of the vital area, whereas the .458 occupies 0.11% of the vital area. It's true, it is 25% larger... but in the grand scheme of things.... it is really only 0.02% more effective if your hoping your bullet diameter will save you. Statistically, that is almost insignificant.

 

[Nhoro]

Larger diameter bullets have nothing to do with accuracy and hitting the vitals. In fact I think accuracy decreases with increasing recoil. This discussion is about an increase in the size of the hole in the vitals. The lungs only bleed around the bullet wound, so 25 % increase in diameter= 25 % more blood and maybe 25% quicker for the animal to go down. There is a general agreement across the industry that a larger diameter results in putting an animal down quicker. An animal that is hit harder goes down quicker. I don’t think anyone would disagree with a 505 Gibbs hitting harder than a 375 h&h

 

[1dirthawker]

an interesting conversation. some thoughts, it seems that reliably and repeatably a larger bullet is worth using on large game. does a larger bullet hit harder if both have the same energy (ft lbs)? i would say so. maybe "hit harder" would be also said to "have more effect".

for instance, with a 375 h&h, would you rather use a 235 gr bullet or a 350 gr bullet on a cape buffalo? i suspect most would argue for the 350 gr bullet. why? energy for both is nearly the same. one could shoot a solid bullet out of both and get similar energies, but why would the heavier one be chosen by nearly everyone? i suspect because of momentum, the ability of the heavier projectile to maintain its forward speed after hitting tissue. of course, a shot directly to the brain would end up the same with either bullet.

but...hunting is seldom so tidy as to offer such a perfect resolution to our fast approaching dangerous game. so then one must ask, is bigger better? lets not go round and round about how one gun recoils more and is harder to shoot well (a valid argument for some) but strictly focus on shooting and animal with softs or solids in the same place, which bullet would have more effect? it would seem most PH's would err on the side of caution with their generally larger rifle calibers. I believe for years that the 2150 fps with a 480/500 gr slug has been a gold standard as a stopping rifle.

as so well stated above by Nhoro, yes, this is a bit more of extreme than the 416 vs 458 question but it does make the same point i believe.

IVW has been a proponent of heavier bullets 350/380 gr. in the 375 h&h, stating that they hit buffalo harder than the 300 grain bullets. i suspect his anecdotal evidence sustains this belief and i would be hard pressed to say he was wrong.

so, i suspect, yes the 458 hits "harder" (has more effect) than the 416. there are a lot of PH's that vote with their wallets and bet with their lives on this principle.

 

[Tokoloshe Safaris]

For the fun of it throw the .404J into the mix!

 

[bruce moulds]

25% increase in diameter = 25% increase in radius.
area = pi r squared where pi = 3.142 and r = radius.
so the surface (frontal) area of the bigger bullet is more than 25% bigger.
bruce.