Fact checking Ashby

[Beendare]

There is a professor peer reviewing the Ashby stuff over on AT and -Spoiler alert- if you drank the Ashby and Ranch Fairy Koolaid… you are going to be dissapointed in your idols.

On AT you can search the posts by Ugly Joe- his nickname over there.
He posted a couple of videos on Youtube, this one points out how Ashby misapplied the Physics on his studies on Mechanical Advantage. This vid is short and sweet.
His vid captures why a 2 blade is so effective as a penetrator ……and why the short wide 3, 4 blades have more resistance.

its titled, “ The myth of mechanical advantage and the 3:1 ratio” by ChemprofJSpencer

HERE
His additional commentary on AT backs what we have known for centuries; heavier arrows are a big factor in arrow penetration…much more than FOC. It seems Ashby putting it at #3 is wishful thinking.

He also has a 45 minute vid that goes through FOC. Its long and math heavy, He analyses the compressive portion of the launch, something no one else addresses- he captures arrow forces though he uses arrow mass as a constant. ( in the real world, its not) The conclusion is there is advantages to some foc.

We all know more tip weight needs more arrow spine…and his followup comment to that on AT is that this added arrow mass can account for much of the additional penetration advantage Ashby attributes to FOC.

The bottom line on all of this and all of the experienced guys will be saying; DUH!

We need an arrow that can reasonably handle whatever tip weight ( who knew that the Easton engineers were right all along?) ….so it won’t be a surprise to the experienced bowhunters that massive FOC is a destabilizing force on the launch. Easton was right, FOC somewhere in the teens or there abouts is about the perfect equation for stabile arrow flight and good arrow performance.

Professor JSpencer said this was all prompted by the Asby foundation article in Dallas Safari club, “ That is so wrong” where they misapplied the physics in their recommendations.
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Its all vindication for what the many of the experienced guys have been saying for years….including myself.

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[Beendare]

This all does beg the question; Who is the Ashby foundation?

Why have they not peer reviewed these studies for accurate info?
Why are their studies clearly lacking in scientific method?
Why hasn’t Ashby ever published the complete data for others to peer review?
( What is the margin of error for an average longbow shooter doing these studies- the scientists would say a lot)
With the newly formed foundation, why havent they done controlled studies with a Hooter Shooter Producing all data and study criteria for others to peer review?

( The only time I know of Ashby revealing full study parameters was when his Extreme FOC study was revealed to show he did it with rubber bands and weighted soda straws. It seems he still does this in his seminars)

 

[4fletch]

who knew that the Easton engineers were right all along?)

Easton and Bohning tell you then show you when they make a claim. Hard to argue with that.

 

[BDRam16]

Can’t wait to take a look at it. I have often fallen just short of calling Ashby a crackpot and that the people who buy wholeheartedly into it naive. When I heard him talk on the Meateater podcast it further cemented my belief. He contradicts himself multiple times throughout the conversation. I don’t care what broadhead or arrow combination you shoot. The most important factor short of shot placement is a 100% tuned bow. I can’t imagine how many guys are out there blaming penetration issues on whatever they want and if they were to paper tune their bow it wouldn’t even be close to a bullet hole. A middle of the road weight arrow with a sharp broadhead out of a properly tuned bow will kill any big game animal in North America. You don’t need 600 grains at 120FPS with a 4 feet difference in your 20 and 30 pins to kill an elk.

 

[Dos Perros]

Does Ugly Joe point to fraud, or ignorance?

 

[Billy Goat]

Wait for it.........

 

[2Stamp]

It's comical that this generates so much controversy and butt hurt. Yes, the "church of the EFOC" thing gets really annoying and seems unnecessary. Take what you want from the factors (or what you know works for you) and drive on.

 

[2Stamp]

Can’t wait to take a look at it. I have often fallen just short of calling Ashby a crackpot and that the people who buy wholeheartedly into it naive. When I heard him talk on the Meateater podcast it further cemented my belief. He contradicts himself multiple times throughout the conversation. I don’t care what broadhead or arrow combination you shoot. The most important factor short of shot placement is a 100% tuned bow. I can’t imagine how many guys are out there blaming penetration issues on whatever they want and if they were to paper tune their bow it wouldn’t even be close to a bullet hole. A middle of the road weight arrow with a sharp broadhead out of a properly tuned bow will kill any big game animal in North America. You don’t need 600 grains at 120FPS with a 4 feet difference in your 20 and 30 pins to kill an elk.

I'm just starting that Meateater episode this morning coming into work.

However, I read some of the Ashby stuff a few years ago after a couple less than desirable outcomes. I didn't chase the EFOC thing, but looked at structure integrity, arrow flight (a lot better tuning on my part), increased my point weight (and overall arrow weight), and the type of BH I was using. My outcome was a 480-510gr arrow (on two different bows), with FOC in the mid to high teens, that flies awesome and penetrates really well.

 

[540-Virginian]

This all does beg the question; Who is the Ashby foundation?

An ophthalmologist who blew four marriages because he was too busy spending money to argue what he believed was the only way to kill a water buffalo...

If only YouTube existed when he started, then maybe he would have gotten a nutrient supplement endorsement deal called "Ashby Juice: With a sugar FOC of 30%!!"

 

[540-Virginian]

Wait for it.........

 

[BDRam16]

View attachment 344831

 

[Beendare]

Does Ugly Joe point to fraud, or ignorance?

I would say its more a lack of understanding on Ashby's part of the factors involved.
What makes it egregious is he claims to be the expert on the subject.

Professor Spencer shows in painful detail where Ashby went wrong in his assumptions.

The one thing you realize when you see Professor Spencers other video, a bow shot arrow is an extremely complex equation. I asked him about the lack of accounting for arrow mass variation in his FOC vid...and he intimated this brings on a whole added level of complexity to the equation- that says a lot when you see guys making analogies to throwing a baseball...or bullets. None of these examples are germaine to a bow shot arrow.

Look, Nobody is trying to insult Ashby. Its not insulting to question studies that are portrayed as 'Scientific' ...and instead is just a series of personal observations.

The professor is going at this from purely a mathematical and physics perspective as we don't have accurate data and study controls from Ashby.

One interesting note is the commentary that shooting into Ballistic gel is not even applicable to shooting an animal. literally apples and oranges.
He says throw all of those Youtube tests out the window. He has a long and very complex Fluid mechanics video for his students....but suffice to say that common sense tells us that the variable density in animals is far different from the grabbiness [my scientific term- grin] of ballistic gel.

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[Beendare]

Personally, I think this arrow advice could have been simplified.

1) Its a fact that a heavy arrow will penetrate better than a lighter arrow, all else equal. The heavy arrow absorbs more of a bows energy.

2) But we also know that light arrows have been killing critters for hundreds of years.

THIS TELLS US THERE IS A HAPPY MEDIUM

So the fact of the matter, a bow shot arrow is a very effective killer. Now, if you are only shooting short hunting shots, then a extra heavy arrow has certain advantages. The disadvantage is trajectory at longer ranges.

A guy that wants an all around setup will get very good performance with an all around arrow. There are minor tradeoffs in these setups from 370g-550g arrows and a multitude of BH combinations. The accepted logic is to use a very efficient BH is you are on the lighter side....and make sure you have enough arrow behind the bigger less efficient BH's.

Pretty simple common sense concepts^....but that won't get anyone their own channel on YouTube or speaking engagements at Pope and Young...grin.

 

[Billy Goat]

At some point the weight (mass) becomes a diminishing return. It would be nice to know where exactly. It's likely way past anything possible.

I'd think a 350k grain arrow from a 48# bow wouldn't actually have any penetration, so at some point you get a peak before the downfall.


It would just be nice to know where that actually is.

 

[Beendare]

At some point the weight (mass) becomes a diminishing return. It would be nice to know where exactly. It's likely way past anything possible.

I'd think a 350k grain arrow from a 48# bow wouldn't actually have any penetration, so at some point you get a peak before the downfall.


It would just be nice to know where that actually is.

I think you are missing how effective a bow actually is.

I did a little experiment with my light but well tuned 40# recurve and a 375g arrow and 2 blade BH last spring. I shot 2 hogs on the ranch I can hunt, short shots and not really big hogs...about 80#, 120#...but blew right through them. I mean the arrow did not even slow down. Heck, the KE on that setup is worse than anemic...less than 40 for sure.

I'm not recommending light arrows....but I am saying that a bow is an incredible killer ...especially if you match the BH to the bow and arrow. My current recurve hunt setup just blows through everything including moose; 48#, 553g arrow and a 2 blade.

So when guys say I should be shooting a 700g arrow...or a 60# bow....the question is why? So my arrows can bury further in the dirt? Some crackpot bone breaking threshold?

All I'm saying is apply common sense. We don't need elaborate physics calc's to understand some of these factors....or tell us that a decent weight arrow works well.

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[Billy Goat]

I think you are missing how effective a bow actually is.

I did a little experiment with my light but well tuned 40# recurve and a 375g arrow and 2 blade BH last spring. I shot 2 hogs on the ranch I can hunt, short shots and not really big hogs...about 80#, 120#...but blew right through them. I mean the arrow did not even slow down. Heck, the KE on that setup is worse than anemic...less than 40 for sure.

I'm not recommending light arrows....but I am saying that a bow is an incredible killer ...especially if you match the BH to the bow and arrow. My current recurve hunt setup just blows through everything including moose; 48#, 553g arrow and a 2 blade.

So when guys say I should be shooting a 700g arrow...or a 60# bow....the question is why? So my arrows can bury further in the dirt? Some crackpot bone breaking threshold?

All I'm saying is apply common sense. We don't need elaborate physics calc's to understand some of these factors....or tell us that a decent weight arrow works well.

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Right, all I'm saying is at some point it doesn't work.


A 350k (350,000) grain arrow, shot out of a 48# bow, isn't likely to go anywhere.

I'm chasing a theoretical point, but somewhere it has to decline.


350k grain is 50#. So there is a reason to my numbers.

Where is the top of the parabola? Likely it doesn't keep climbing, tho maybe it does til 20k gr or something. Tho I think it's less like a parabola, more like a plateau. Rises to a point, stays pretty constant, then falls off.

 

[BDRam16]

Right, all I'm saying is at some point it doesn't work.


A 350k (350,000) grain arrow, shot out of a 48# bow, isn't likely to go anywhere.

I'm chasing a theoretical point, but somewhere it has to decline.


350k grain is 50#. So there is a reason to my numbers.

Where is the top of the parabola? Likely it doesn't keep climbing, tho maybe it does til 20k gr or something. Tho I think it's less like a parabola, more like a plateau. Rises to a point, stays pretty constant, then falls off.

I’m always wondering this too, but it’s so hard to define because it would be dependent on your set up. At what point does the mass increase/velocity decrease result in a loss of energy delivered. Of course the opposite is also true, at what point is it too light and too fast?

 

[Beendare]

Right, all I'm saying is at some point it doesn't work.

Ok gotcha.
There was a website that did some testing on this back in the day, Archery Report or something like that.…Im not sure its still around but it was good stuff.

The real question is at what point does KE fall off? As I recall the KE and momentum fall off around 1800grains but I cant remember the exact number. Its surprisingly high. Its the reason why guys shoot 1200g arrows for elephants and hippos.

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[OR Archer]

I’m always wondering this too, but it’s so hard to define because it would be dependent on your set up. At what point does the mass increase/velocity decrease result in a loss of energy delivered. Of course the opposite is also true, at what point is it too light and too

That won’t happen within a bows effective range. There is a point however where the gains in momentum don’t outweigh the loss of speed(trajectory) in my opinion. I think this is where people start to go backwards when that point is crossed. Range estimation and also follow through on the shot become very critical when lobbing big heavy arrows at such slow speeds.

 

[OR Archer]

The real question is at what point does KE fall off? As I recall the KE and momentum fall off around 1800grains but I cant remember the exact number. Its surprisingly high. Its the reason why guys shoot 1200g arrows for elephants and hippos.

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Have you ever shot an arrow that’s 1000+ grains? Built some for Neil Summers for an elephant hunt. He shot them out of a Mathews Monster. There was actual felt recoil from the bow trying to push that heavy of an arrow. Crazy stuff.