Debunking the TKO myth

[Kachok]

I have never killed an elephant, so I would be crazy to argue the finer points of Bells track record with his little Mausers. I personaly think just surviving that many kills is testament enough that in the hands of an expert a 6.5x55 or 7mm Mauser will drop them cold. Anyway back to the issue at hand, even if there is ANY validity to the TKO formula on headshots it has no aplacation to soft tissue damage with modern expanding bullets. I have looked and looked I have yet to find anything more effective on North American game per unit of energy then a high SD relativly small diamiter spritzer bullets, flat solids drive deep but don't make the quality of wound canal that a modern expanding bullet does.

 

[mr.trooper]

Kachok:

I'm trying to give you the benefit of the doubt, but you just busted my balls in another thread for nay-saying these same kinds of formulas.... now you have your own thread doing the same?

I suggested in that same thread that the OP use semi-wadcutters if he insisted on using a 45acp for deer, and you busted me for that as well... now in this thread you say that "flat nose bullets are the best killers in the ballistic world"?

If I have you wrong, then by all means explain.

 

[Ridgerunner665]

Quality of the wound channel...

I know what you mean by that (you pour out the tissue), but the big ole boolits kill just as quickly.

I've seen it too many times...I've always liked the 308, it has always given me bang/flops on deer, and is pretty good on bear too...but it has never bang/flopped a bear for me. (not saying it can't, it just hasn't for me)...I use 165 grain Nosler Ballistic Tips, I always get complete penetration and innards turned to mush.

The 45-70 has bang/flopped everything...bear and deer. 1/2" hole going in, golf ball size coming out (standard pressure loads, I haven't killed a deer yet with the high octane loads)...nothing turned to mush...but massive blood loss every time.

 

[Kachok]

No you missunderstand. Flat solids are efficient killers, that does not mean that they are suitable at 45ACP speeds. Don't EVER try mixing up what I am saying because I don't flip flop. All the efficiency in the world does not make up for a complete lack of energy. Nothing wrong with 45-70. Plenty of speed and energy with SPs of FN bullets. More recoil then you would have to put up with but there is somthing just plain fun about big bores no doubt.

 

[CraigC]

Of course it seems silly, when you take it completely out of context and apply it in a way which was never intended. In the purpose for which it was intended, it is just as viable today as when it was first written. No, you don't use it to compare heavy solids with high velocity small bore expanding pills, or expanding bullets of any kind. However, when used to compare relatively low velocity, large diameter, heavy for caliber non-expanding bullets, it is a VERY good tool for comparing cartridges.....to each other. Why? Because unlike the vastly overrated muzzle energy, it lends more importance to bullet weight and diameter than velocity. This is particularly useful in comparing big bore sixgun cartridges, where velocity is not in adundance but real killing power is. Killing power which is reliant upon bullet weight and diameter.

Is it the all-encompassing last word on cartridge effectiveness? Is it perfect? Certainly not. Is it a useful tool in comparing the effectiveness of large, heavy, non-expanding bullets? Absolutely, but only to each other. It is certainly FAR more useful than muzzle energy, which in this context is completely meaningless. If everybody firmly believed in all the energy rhetoric, handgun hunting would not be possible.

 

[Ridgerunner665]

Amen to that...

 

[Kachok]

If it cannot compare slow big bores to fast moving spritzer bullets then WHY do people keep doing it?? Sure it you are comparing the .45-70 to the .50-90 the TKO formula will tell you the .50-90 packs more punch, but really and truthfully it cannot tell you anything that even a small dose of common sence cannot. Hence not really useful. If a formula cannot compare the performance of 100gr 6mm bullets as well as 500gr Solids it is not much of anything. In the case of the TKO it is HIGHLY misleading to people who don't understand that it cannot compare a 260Rem to a 338Fed. Hence it should cease to be. There is nothing that TKO can compare big bore vs big bore that any other less misleading formula cannot.

 

[mr.trooper]

You have said in the past that "shot placement is a given".

If this is true, then why bother with any of these formulas?

 

[CraigC]

If it cannot compare slow big bores to fast moving spritzer bullets then WHY do people keep doing it??

YOU are the only one I see doing it!!! Yourself and some knuckleheaded gunwriters who started your particular bandwagon rolling.

Sure it you are comparing the .45-70 to the .50-90 the TKO formula will tell you the .50-90 packs more punch, but really and truthfully it cannot tell you anything that even a small dose of common sence cannot.

Hogwash. It depends completely upon the diameter and weight of the bullet in question. Common sense doesn't appear to be too common 'round these parts.

In the case of the TKO it is HIGHLY misleading to people who don't understand that it cannot compare a 260Rem to a 338Fed.

You're blaming the formula for the lack of understanding on the part of the moron with the calculator? Isn't that kinda like blaming guns for crime???

Hence it should cease to be.

Or maybe YOU should cease to use it and rant about it until YOU understand it.

There is nothing that TKO can compare big bore vs big bore that any other less misleading formula cannot.

Such as???

 

[Kachok]

Wow so much to pick apart so little time. I do understand the TKO formula, I understand the context in which it was written, i understand what is can and cannot accuratly compare. I also understand that it cannot compare ballistics of large/slow to smaller/faster which makes it inharently flawed in the context of the American hunter or anyone that is not taking headshots on very large game. I have had people throw TKO formula in my face since I was a kid, not gunwrightes but people who honest to God did not know any better. I bought it at first but then I did my own reserch. And what do you mean "such as" such as nothing. There is nothing that the TKO can tell us about larger calibers that Lethality Index or OGW or a dozen other cannot. None of them are perfect but of all the ones I have seen TKO is by far the most inaccurate in terms of relative wounding capabilities, if you don't beleve that read the OP.

 

[mr.trooper]

None of them tell you anything, beyond a subjective number.

 

[Kachok]

Here are a couple quotes from people that have much more experence with ballistics/hunting then any of us.

The horrific error in putting your faith in either kinetic energy or a Taylor Knock-Out value should be obvious. If you believe in TKO, a 12 gauge Foster slug is 13 times more deadly than a .223 Remington, almost four and one half times as lethal as a 30-30, and over 350% more deadly than a .308

Taylor himself admitted that there was no appreciable difference in the killing performance of the various .400’s, .415’s, .450’s, .465’s, .470’s, .475’s and 500’s on dangerous game when loaded with reliable bullets of sound construction (Ah ha! Here lies the rub.). The TKO, as most commonly interpreted, exaggerates any difference that might exist because it makes the bore diameter equally as important as the velocity. When comparing a .450/.400 NE and a .500 NE using his formula, the latter is calculated to be 55% more potent, even though Taylor himself admitted to them being very similar in killing performance. So, things do not appear as they seem

So John Taylor himself admited that his own fomula was faulty and yall are blasting me far calling it faulty

 

[Ridgerunner665]

Thats not what I'm blasting you over...

And I'd be careful about making blanket statements about "any of us"...you might be surprised at the identities and backgrounds of some of these fine folks here at THR.

I'll admit there are at least 10,000 "internet commandos" and "know-it-alls" for every legitimate expert here...but there certainly are some VERY knowledgeable folks who read and post on THR (some of whom you've probably heard of)...I learned that lesson the hard way myself. (it wasn't exactly "the hard way"...it was fun)

I still miss Shawnee...he would have had a ball with this thread, LMAO...him and that 243. (no he was certainly no expert...but he was entertaining)

 

[Kachok]

Oh no doubt. I have studied external and terminal ballistics for years, but I know I am not the formost expert here by a long shot. But I have to say that all of the lagit experts I have ever spoken with will tell you the same conclusion I have come to.
Look at my OP the comparison between the shotgun and 308. The fact that the TKO formula rates the slug almost 4 times more powerful and yet it does much less tissue damage. That will tell you right there that it is not just a minor imperfection in the system, it is badly flawed. OGW is not perfect either but it only has them at a small margin of differrence. There are many proven examples of this, over and over TKO is highly bias toward caliber, far beyond any advantages larger calibers actualy have in lab tests or in the real world. I am not making this up it is right in front of you see for yourself.

 

[mr.trooper]

Chuck Hawks is not the gun-pope. He isn't even the gun-deacon.

Even if OGW were more effective than the others, that's like taking first place in the Saudi "prettiest goat" competition.

 

[Float Pilot]

In the case of the TKO it is HIGHLY misleading to people who don't understand that it cannot compare a 260Rem to a 338Fed.

Lets see, two outstanding cartridges with sharing the same mother case.

With a 200 grain bullet from a 338 Federal at 2,550 FPS muzzle velocity
You have at the muzzle:
Energy 2882 ft-lbs
TKO 24.63
OGW 995 lbs
IPSC PF 510

(sidebar: For some reason the 338 Fed is not catching on up here in Alaska. The older but deadly 358 Win has a loyal fan base and the wonderful 338-06 is steadily becoming more popular)

With a 260 Remington with a 140 grain bullet at 2,700 fps muzzle velocity.
You have at the muzzle:
Energy 2295 ft-lbs
TKO 13.98
OGW 592 lbs
IPSC PF 380.8

Wherein does your argument in comparing these two lay...?



The advantage of a cartridge like the 260 Rem and it's ballistic older twin the 6.5x55mm is a flatter trajectory, less recoil, better shooter accuracy due to less recoil and less ammunition weight. Not because it is some sort of death ray.

Now at 300 yards, the 338 Federal 200 grain bullet is only going 1,800 fps with a TKO now down to 17.4, 1456 ft pounds and a OGW of 356.

The 260 or 6.5x55 at 300 yards is still going around 2,222 fps and has a TKO of 11.7 and 1,534 ft pounds of energy, plus a OGW of 322 pounds

And the 260 did it while remaining within 3.5 inches of the bore line flight path, while the 338 Federal was twice that high.
And of course the flat shooting 260 continues to catch up and pass the 338 Federal as it cruises out past 500 yards with no problem.

BUT:
When you are in tall grass, the sun is fading, you have two big salmon in your pack and another mile to get back to your plane or camp.....

Which one would you rather have in bear country...??? The 338 Fed with soft point 200 grain bullets or the 260 Rem with that nice sleek and faster 140 grain boat tails.

 

[Ridgerunner665]

Kachok,
You don't have to sell me on the formulas...they all suck, for every point you make with one formula...it can be disproved with another formula.

I prefer to dig a little deeper...into the mechanics of tissue disruption, and what happens with a liver shot versus a heart shot, or the benefits of a high shoulder shot...stuff like that.

The round used doesn't really matter...its where you put it that counts.

 

[Kachok]

Then let it be the prettiest goat, is it a gold standard....NO does it give you a heck of alot better idea then TKO does YES. DO I agree where the 260 and 338 show in the TKO rankings NOT A BIT. I own and frequently use the 260s ballistic twin the 6.5x55 and it stops everything here in in the South including our large feral hogs with conviction, I would have a VERY hard time beleving that the 338fed has almost twice the power. A very very hard time. 6.5x55 is a very common elk/moose rifle in Europe where I lived for four years. They hold it's killing power in the highest reguard, I somehow don't see the 338Fed surpassing that power by that much.

 

[mr.trooper]

The advantage of a cartridge like the 260 Rem and it's ballistic older twin the 6.5x55mm is a flatter trajectory, less recoil, better shooter accuracy due to less recoil and less ammunition weight. Not because it is some sort of death ray.

"Shot placement is a given", remember?

is it a gold standard....NO does it give you a heck of alot better idea then TKO does YES.

Why do you cling to a formula you know and admit is seriously flawed? This is the essence of a fools errand.

 

[Kachok]

Yeah they are all inaccurate. None of them is spot on granted but it is the extent of which the TKO formula is off that makes it so absurd, nobody here can come up with any logical explanation why the 12ga slug did not make as much soft tissue damage as the 308 which it was supposed to dramaticly surpass by a ratio of 3.5:1. That is not just wrong but horrably wrong! No other formula that I have come across except maby the pure energy formula has ever been that far off on anything. Like John and myself have said it is a flawed formula.

 

[mr.trooper]

One piece of garbage is smellier than the others, and YOU sir have exposed it. CONGRATULATIONS!

 

[Kachok]

Here is my point, someone, ANYONE find me a side by side example like this where any other respected lethality formula was off by a ratio of 4-5:1 using controled expansion projectiles. If someone could find me such an example I will eat crow and appologize for every bad word I have ever said about the TKO formula. I am a ballistics hobbiest I have never seen such inaccuracies in any other except the BS pure energy nonsence.

 

[Davek1977]

Amen! this is like comparing dirty diapers to see which smells the worst.....chances are, none are very pleasant, so I'll pass on sniffing any of the competition!!! When comparing "kind of" broken and "broken" neither will give you satifsfactory results....kinda like the comparison going on here. Two wrongs don't make a right, and I've always considered arguing that somehting is "less flawed" is silly. Either its flawed...or its not flawed. In this case, BOTH formulas are flawed, making NEITHER right....just a rehash of arguments shooters have been having for decades.....

 

[Kachok]

Here is my point, someone, ANYONE find me a side by side example like this where any other respected lethality formula was off by a ratio of 4-5:1 using controled expansion projectiles. If someone could find me such an example I will eat crow and appologize for every bad word I have ever said about the TKO formula. I am a ballistics hobbiest I have never seen such inaccuracies in any other except the BS pure energy nonsence.
Sorry for the double post, my computer adheards to the TKO formula so it too is inharently flawed.

 

[CraigC]

...nobody here can come up with any logical explanation why the 12ga slug did not make as much soft tissue damage as the 308 which it was supposed to dramaticly surpass by a ratio of 3.5:1.

There is a logical explanation, you just refuse to hear it. The explanation is that you are applying the formula in a way which was not intended. Period. THE TKO FORMULA CANNOT BE USED TO COMPARE HIGH VELOCITY CARTRIDGES!!!!!!!!!! Why? Because, as said many times before, it was devised to compare big bore, heavweight cartridges firing non-expanding bullets. I don't know why you seem intent on calling foul when it is YOU who are in the wrong in the way you are applying the forumula. The result is NOT relevant because TKO puts more importance on weight and diameter than velocity. So, obviously, the numbers will be skewed when applying it to a 165gr .308 at high velocity. Only a fool makes this argument.

I'll repeat, IT IS ONLY RELEVANT IN THIS NARROW CONTEXT OF COMPARING THE BIG BORES WITH NON-EXPANDING BULLETS......TO EACH OTHER

Flip it around and muzzle energy is equally silly. Because you have cartridges which fire big and slow bullets at low to moderate velocity that kill all out of proportion to their paper ballistics. Now turn around and compare the energy numbers between a .44Mag firing a 330gr LBT at 1350fps to a .223 firing a 55gr at 2300fps. They are comparable in energy but which would you rather have in your hands if a grizzly charged you??? Why? Because muzzle energy places far too much importance on velocity.

Even your OGW puts way too much emphasis on velocity. Look at the .270 numbers. The WSM has a rating 200lbs higher than the WCF with a 150gr bullet and the only difference is 200fps muzzle velocity.

The bottom line is there is no reliable formula for comparing big bores with solids to high velocity rifle rounds shooting expanding bullets.