Taylor KO Factor (TKO) - Hunting Loads

I was reading the article "Gun Notes: A Common Sense Look at Handgun Hunting" under John Linebaugh's writing page. One of the topics within this article was the Taylor KO Factor. What are your thoughts on this subject and the formula?

The attached link provides a little more information on the formula. Scroll halfway down the page to review it.

http://www.africahunting.com/threads/john-howard-pondoro-taylor-1904-1969.3242/

It's a better measure of performance than simple kinetic energy. However I think we all struggle to determine a scientific way to predetermine how a bullet will perform on game when their are realistically too many variables that cannot be factored in. The will to live is a good example. Bullet construction and terminal performance is also important and something equally as important as TKO Value

I agree, lots of variables but its probably the most realistic we have. A 22 caliber bullet at 7,000 fps would have a lot of kinetic energy but which would you rather use against a black bear, a 22 caliber bullet or a 250 gr. 44 magnum.

Dick

TKO to start and then what you learn in the field as you hunt.

I agree, it's not the be all end all, but it's a good starting point. Taking game will help you decide what works best.

Just remember to use it within its limitations as it was intended and it is a pretty good tool.
If I wanted to compare the performance of say a 10mm and a 45ACP given common components and a common use the TKOF formula will give me valid results relative to each other.

I like using the TKO factor, especially with revolver rounds.

I use an Excel file I created to record all of my load data. I have incorporated a formula in two separate columns that automatically calculates both kinetic energy and TKO when I enter the data.

Although it was with a rifle the same physics apply. When I killed that behemoth of a water buffalo I tested bullets against bone and simulated flesh for months. There is no simple formula to apply to any projectile intended for the purpose of killing. There certainly
is a necessity of KE involved to destroy the things that make animals live. In that regard the TKO has some merit.

I read both taylors work and the book about taylor by capstick. All the formulas have their place and none are without exceptions. People dismiss ke and just dont understand what the formula is trying to describe nor how to use it. When used appropriately it gave give you a guide in certain elements of terminal performance and so can taylors but in the end i think both are nonsense used as a stand alone and unlike tko values gun writers use KE to describe that which it was meant to describe. It is simply describing the ability of an object in motion to do work. If there was a projectile out that could handle the velocity of 10000fps it would be very destructive even if it was 22 caliber. Its no secret what works in the hunting realm and newer and better bullets keep changing what we can use effectively. No formula tells it all

My TKO = Big hole in; Bigger hole out. .50 440WFNGC !!

I agree, but how can a WFN be a semi-wadcutter? Sorry, just confused.

obviously you are correct, but in the end does it matter? Everything I shot with either style exhibits the same results. clean holes on both sides and very dead animals.

Question for folks on the forum here.
When calculating the TKO, do you use the caliber of the bullet when fired or the expanded diameter assuming proper bullet function?

karl,

It will be bullet dia. before it leaves the barrel.

Ya, not all hunting bullets expand.

This site has a TKO calculator TKO Calculator