My thoughts on real world applications of the Ashby studies

[pdk25]

I am not sure whether you are being intentionally confrontational. I was referring to the Cape buffalo that I shot broadside as well as one other that was mentioned and at least two others that I know of that didn’t get adequate penetration. Just because I took a four-way shot on the guys recommendation does not mean that I was not aware of anatomy before I left for the trip. There is a difference between knowing anatomy and still thinking you can get the job done and being mistaken and actually not knowing the anatomy. According to the Ashley studies my set up should have been adequate on a bright side shot which it was not. Have I been clear enough for you?

[David P]

No one is being confrontational, your just not hearing what you want to hear. Shot placement and shot selection are the reasons for the failure not the Ashby studies. If no other bowhunter in history had killed a Buffalo maybe you’d have a point. But it’s been done by multiple bowhunters. Ashby’s was testing what the best combination of arrow, weight and broadhead gets the best penetration. Nowhere did he guarantee a pass thru, who would expect him too. There are to many variables. Are you saying you’d have done better with a lighter lower foc arrow? Or maybe a 4 blade broadhead? Ashby listed the variables to get the most penetration possible. But it’s up to the hunter to make the right shot in the right place. No amount of weight of arrow or draw weight can overcome poor shots, that’s part of bowhunting. Is that clear enough for you?

[pdk25]

If I am not mistaken, and I don’t believe that I am, he reported 100% full penetration with certain set ups, with which my equipment met the criteria on the broadside Cape Buffalo.  Similar experiences have been had by others.  You are focused on the quartering away shots, which I have already stated that I would not take again unless I had a much more powerful setup, and still probably wouldn’t.  Did you only become a member here for the sole purpose of giving me grief?  There have been multiple people that have killed buffalo with broadside shots with less energetic setups, less FOC, less heavy arrows, etc.  What I am saying is that, based on the fact that I and others have had less than full penetration at times on broadside buffalo, that you shouldn’t necessarily feel that you will just because the Ashby studies showed 100 percent full penetration under different conditions than hunting.  Do you really think that I shared this because I need a pat on the back.  I posted this, including my personal failures and equipment failures under different conditions so other people might benefit from it.

[George Vernon]

Pat,
I appreciate your sharing of your hunt—successes and failures.  Let me add a bit to your observations of Ashby’s studies.  To his credit, he tried to normalize the study of arrow penetration in real skin, tissue and bone.  But working with biological systems is tough.  So many variables, and most outside the experimenters control.

I’ve read all the reports and looked at the regression analysis he did while examining all the variables he tested.  The regression analysis attempts to see what variable(s) can actually be ‘modeled’ using a formula to predict results that match experimental measurements.  It’s been a while since I went through all the reports and statistics, so I may not cite everything just right (a dangerous thing to do on this site).  Statisticians use the ‘r squared’ value to say whether or not a variable can be accurately modeled.  R-squared is a number displayed in percents or as a decimal fraction.  For example, an R squared value of 0.5 or 50% can roughly be interpreted as the model will match reality about half the time.  Most statisticians don’t get excited about a model until the value of R squared gets above 0.8 or higher, meaning the model and reality will agree 80% of the time or more.  Of all the tests done by Ashby, only one variable was statistically shown to have a predictable effect on penetration and that was the amount of FOC.  I believe this variable was the only one to show an R squared value of more than 0.5.

Now hold on with the poisoned arrows.  All of the data collected is valuable in the sense it gives us some empirical insight, but FOC is the only one that was consistently able to explain the real world results.

So, Pat, I’m not surprised to hear your single bevel results did not show great penetration.  It’s one of the variables that matched predicted results less than half the time.

I understand many folks think Ashby’s results are infallible and will flame my comments.  But folks, the statistics I’m quoting are not mine, they are the ones Dr. Ashby published.  I’m just trying to say which ones are most likely to be replicated by others.  And I believe the only one that fits that criteria is the amount of FOC.

[GCook]

I hear what you're saying Pat.  And I agree his findings were, having merit, by less than conclusive and inclusive. 
However that can be said for many of the scientific findings over the centuries.

[hybridbow hunter]

Quatering away on buff cape or Asian should be a no go with trad gear. Hard quatering need an entry point really far back but a long travel to the vitals and on a moderate quatering animal a shot in the rib cage will have poor penetration more often.
That draw is pretty accurate and explain why. Arrow has a high odd to be internally deflected along the OUTSIDE rib cage and in case it penetrates the ribs you need to cut more rib bone on one or 2 ribs than a broadside or little quatering toward on a high lung shot.
I hunted water buff in 2016 and used a 920 gr arrow flying 175+ fps and an tuffhead BH 300 on a 150 gr steel glu in glu on adaptator
I didn’t face poor penetration but scarce blood and little longer than expected time until death for the critter.
From that trip and some other African experience on rather heavy animals I really experienced no advantage with 3:1 “Ashby” design over low profile/ extreme sharpness BH like ironwill In fact I did experience much penetrating power with the last out of my bows.
For my next trip (cape buff) I know will use regular 200 or 225 gr Ironwill BH with no bleeder screwed on 150 gr steel insert and a little lighter arrow in the 800-850 gr flying in the 175-180 fps range.

[hybridbow hunter]

Some pics from water buf skeleton quatering away and slightly toward

[Terry Green]

Interesting.... anyone know how and when Ashby started the FOC study???

Right here 1st month of Tradgang...... crazy.....

https://www.tradgang.com/tgsmf/index.php?topic=127087.msg2258505#msg2258505