Who has snorted the Fairy Dust?

[BTaylor]

KE is defined as energy of mass in motion. Even though KE is dealing with the arrow speed x speed x weight, it is actually a good indicator of what the bow is capable of doing. And it is a good indicator of penetration capabilities.

This prolly isnt technically correct but I have always kind of viewed KE as the amount of energy the bow puts into the arrow and momentum as the the amount of work the arrow can do. The effectiveness of that work being impacted by the type of broadhead out front. Effectiveness of work = penetration potential.

 

[phatkaw]

And let's not kid ourselves....90% of our decisions, especially as it pertains to hunting, are based on anecdotal evidence. Ranch Fairy, Ashby, Dudley, Eberhart....the reason there are so many variances in approaches is because we aren't dealing with absolutes.

90% of my hunting decisions are based on what I have learned through my journey!

The other 10% I'm trying something new...

 

[Iron_llama]

Fairy and rocket man have both eluded to some data they have showing the slower projectiles getting "better" penetration.....i think it's newtons 3rd law? For every action there is an equal and opposite reaction...the faster that arrow going the more force trying to stop it. The foam target show that easy enough....hold ur arrow.in ur hand and apply slow steady downward pressure and see how far u can sink it....now do the same but slam that arrow in with as much force and as fast as u can

I think I remember the argument you're referring to. Apparently resistance due to air pressure is linked to the square of velocity. So, the faster your arrow goes, the more it gets slowed down.

* found it on the NASA website:

 

[Crawdaddy4]

90% of my hunting decisions are based on what I have learned through my journey!

The other 10% I'm trying something new...

Part of that 10% for me is chasing something new and shiny!!

 

[Plebe]

What does that even mean?

It means a direct correlation to discussion of bows and arrows is not particularly obvious. In other words, these examples are obtuse.

Case in point, the hand out the window of an accelerating car shtick. Ashby uses that one in his papers. Go faster, feel drag increase. Got it. But my hand always continues to move through the medium (air), overcoming the resistance. It does not come to a stop until the vehicle is slowed to a rest. So what's the bottom line?

If we we're to consider our targets (deer) bags of water, as much of Ashby's math denotes, it's not entirely impossible to discover minimum sets of variables for V and M to penetrate through a water column of a measured distance. Call it the H2O penetration threshold data set.

Ashby sort of avoids the math when it comes to the friction problem (that's right, deer aren't waterbags), probably because it's a lot more complicated. He skips to the pinnacle of worries with field studies tackling a bone breaking threshold. Not unhelpful, and not obtuse. We have a number, 650! Still, there's a lot more to the story of friction that's unsaid.

Hence my attempt at a failed analogy, which clearly succeeded in failure, lol. In action, friction overcome by speed...ever see a Nascar victory burnout?

As for bullets and water.....

What does any of it mean for killing a deer, precisely?

 

[Plebe]

I think I remember the argument you're referring to. Apparently resistance due to air pressure is linked to the square of velocity. So, the faster your arrow goes, the more it gets slowed down.

* found it on the NASA website:
View attachment 90642

It's also available in the Ashby study. lol.

In the DIY sportsman video posted by @woodsdog2, DIY Garrett states the measured speed loss to 30 yards for a couple of his setups, and indeed the heavier slower arrow loses less speed. Nevertheless, the faster arrow is still moving faster.

 

[kyler1945]

Ashby thought of interesting questions to ask, and even more interesting ways to answer them.

Ashby the statistician would not make it very far in that line of work.

 

[Weldabeast]

I can't accurately articulate my point and in the scheme of things it's not very important..... Someone smarter than me would have to explain it....my arrows fly good, I shoot them well, and they kill stuff real good...

This "argument" does get old quick. The only reason I brought it back up is because i have always thought those broadhead tests were bunk and agree that targets don't correlate to critters

 

[woodsdog2]

I wonder how many slugs are needed? His lightest arrow tested in the compound bow (379 grains) produced .496 slugs. His heaviest trad set (703 grains) only produced .428 slugs.

View attachment 90616

View attachment 90617

Probably enough to ensure a slow bow can still be used on any legal big game animal is my hunch. Surely his trad setup isn’t shooting as fast as his 72-73ish lb compound.

 

[woodsdog2]

KE is defined as energy of mass in motion. Even though KE is dealing with the arrow speed x speed x weight, it is actually a good indicator of what the bow is capable of doing. And it is a good indicator of penetration capabilities.

Yep! KE is a great predictor of the ability of a bow to convert potential energy to kinetic energy, i.e. the bow’s efficiency. I’m not sure it’s as reliable of an indicator of the arrow’s ability. That shove or push is just one part of the equation. The broadhead and arrow setup are the other side of that equal sign.

 

[Plebe]

Probably enough to ensure a slow bow can still be used on any legal big game animal is my hunch. Surely his trad setup isn’t shooting as fast as his 72-73ish lb compound.

Surely. And without a doubt DIY Garrett has an understanding of differing limitations between his setups.

But on paper, he gets more slugs from a light setup with a compound than his RF approved trad set.

I just wish we could put our finger on how the data applies, more specifically. Like, do we really need double the slugs at half the speed? I don't think so.

So where's the sweet spot? When is enough more than ample? And when is more than ample less than ideal?

These are the questions. imo.

 

[woodsdog2]

I want to make it clear that I’m not judging what people want to shoot, how they want to shoot it and what their expectations should be at all. I just think speed isn’t everything and neither are super heavy arrows. I’m more of an advocate for a balanced setup but with the nod to a bit heavier arrow coupled with a structurally sound coc head for the uncontrollable circumstances. Plus, I hate the loud twang of a fast bow shooting a loud arrow….. I just see and feel the inefficiencies oozing out of everything like green slime in a ghostbusters movie.

 

[Crawdaddy4]

If I had to point people to one philosophical tenant to abstract from all Ashby’s surmising and reports, it’s simply this:

“You should always use the heaviest arrow possible that has a trajectory you still find acceptable.” - Dr. Ashby

 

[Weldabeast]

Don't mechanical broadheads have a minimum KE listed to "function" correctly

 

[woodsdog2]

Don't mechanical broadheads have a minimum KE listed to "function" correctly

Yes. Many do!

 

[krub6b]

Don't mechanical broadheads have a minimum KE listed to "function" correctly

The "easy open" ones used to be 40# of KE to open

Sent from my Pixel 3 using Tapatalk

 

[Plebe]

I can't accurately articulate my point and in the scheme of things it's not very important..... Someone smarter than me would have to explain it....my arrows fly good, I shoot them well, and they kill stuff real good...

This "argument" does get old quick. The only reason I brought it back up is because i have always thought those broadhead tests were bunk and agree that targets don't correlate to critters

There's no equal substitute for the real thing. But doing that kind of study on Whitetailed Deer is about impossible.

I still think there's comparative takeaways from broadhead tests, from one design to another. That may not answer which broadhead is more or most lethal, but does offer some idea of aspects of performance relative to other options.

 

[woodsdog2]

I just wish we could put our finger on how the data applies, more specifically. Like, do we really need double the slugs at half the speed? I don't think so.

So where's the sweet spot? When is enough more than ample? And when is more than ample less than ideal?

These are the questions. imo.

Agreed! In Joe Bell's excellent book entitled "Technical Bowhunting" he has a whole chapter on the importance of momentum compared to KE when it comes to hunting bow and arrow setups. The book was published in 2008 long before the Ole' RF. Bell referenced several hunters, especially western hunters who were struggling with the need for speed for a flatter trajectory on longer distance game shots, but also were experiencing a great deal of wounding loss. So, they were getting the arrow on target but still having issues with penetration. The conclusion for many was a heavier arrow in the 425-460gr. range which proved to be a more optimal approach for a balance between trajectory and punching though a bigger game animal. Other noted benefits of heavier arrows include less deflection on angled shots (much relevancy for saddle and treestand hunters), less violent arrow dynamic upon release which equates to easier tuning and better overall broadhead flight (especially for big CoC broadheads), quieter setups and shots, and in some instances, a 10% increase in penetration potential (momentum in slugs) which essentially equates to an arrow shot from a 60lb bow equaling the same momentum as if the bowhunter were drawing a 70lb bow. This opens up possibilities for many more archers and scenarios in which we ultimately should be striving toward.

 

[kyler1945]

There's no equal substitute for the real thing. But doing that kind of study on Whitetailed Deer is about impossible.

I still think there's comparative takeaways from broadhead tests, from one design to another. That may not answer which broadhead is more or most lethal, but does offer some idea of aspects of performance relative to other options.

We could have the data to easily tease out what factors correlate most strongly with lethality on whitetail deer after a single season.

All it would take is a simple app for a hunter to drop in the 10-20 variables that we’re looking at. Get several thousand people to submit data, and you’re in business.

Two problems as I see it:

I’ll pay to build the app - but I ain’t paying to fund the campaign to convince people to use it.

Though not necessary for us knuckle draggers to make loud noises on what it all means, there would be a cost to pay properly trained folks to analyze the data. Maybe someone knows someone who knows someone who knows somethin bout it. Grad student, intern, etc.

We could also do the same thing here. I’ve already asked the mods, but they can’t commit to keeping the thread clean for data drops. It’s not a reflection of them, it’s a reflection of us not being able to keep our opinions to ourselves.

I’ll make the offer again - if anyone is serious about collecting this data in an adult way, I’m happy to get involved with time and dollars. It’s not hard to dream up the scheme. It’s getting a few people to take it seriously.

 

[Iron_llama]

This "argument" does get old quick. The only reason I brought it back up is because i have always thought those broadhead tests were bunk and agree that targets don't correlate to critters

At some point it's only an argument because we find it amusing to argue about it. At the end of the day we'll all hunt with whatever legal projectiles we choose and loose no sleep over what anyone else hunts with.