Black Eagle Arrows???????

[cuerro viejo]

The point I was trying to make is that in order to get a sub-500 gr. high FOC arrow one would have to use a pretty stiff/light shaft, and in doing so would give up durability which is counterproductive to Ashby's #1 criterion for arrow penetration.

You are correct in that the point weight would have little to no impact on the durability of the shaft.

383gr BE rampage 16% FOC
451 gr BE deepimpact with 15% FOC

I used wrong pin the other day and my back stop is a brick wall. I bent the cert and didn't hurt the arrow

 

[MattB]

with todays efficient cam design Ashbys studies arent as relevant on arrow weight especially on north american game animals.

That is an interesting comment, can you explain how high efficiency cam designs influence the physics related to arrow penetration?

 

[cuerro viejo]

Higher the KE rating of a bow more energy that makes/transfered it to the arrow, thus the higher IBO/speed ratings for todays bows vs same poundage of bows 10 years ago

Momentuem is mass x velocity.

Ashby studies were mainly geared toward traditional bows, they lack high energy transfer.

In momentum if you don't have the velocity you have to make up for it with mass. You also get to a point were you move backwards in effectiveness if you go to high.

You question sub 500gr arrows, why not question sub 2000gr arrows?

 

[BSeals71]

I just bought some Black Eagle X - Impact 300's.
They seam pretty nice but haven't had the chance to shoot them long range yet.

411gr 28", 16% FOC Firenock outsert & Eason Injexion insert for added weight.

 

[MattB]

Higher the KE rating of a bow more energy that makes/transfered it to the arrow, thus the higher IBO/speed ratings for todays bows vs same poundage of bows 10 years ago

Momentuem is mass x velocity.

Ashby studies were mainly geared toward traditional bows, they lack high energy transfer.

In momentum if you don't have the velocity you have to make up for it with mass. You also get to a point were you move backwards in effectiveness if you go to high.

Ashby's work found that KE (which is more heavily reliant on velocity) was not a predictive factor in arrow penetration, and that heavy bone penetration thresholds were driven largely by arrow weight regardless of velocity, so I am still not sure how cam efficiency that has any impact on the relevance of his findings. There were strong correlations shown for both momentum and arrow weight on soft tissue, but I think we can agree that performance on soft tissue isn't where his work is most relevant.

You question sub 500gr arrows, why not question sub 2000gr arrows?

If you think I am arguing for using a 500 gr. arrow, you are missing my point.

 

[cuerro viejo]

You have to try really hard to get a 500gr arrow plus theses days. Point was more isn't always better hence no 2k gr arrows


You asked why KE was relevant in penetration, and I explained it. Its nothing more than measure of how efficient bow design is. Higher the efficiently higher the speed per poundage

Ashby's studies where based off momentum thus the reason he suggest momentum numbers for different animals. If you don't think speed is relevant in penetration I don't know how to change you mind other than shoot same arrow weight at different speeds and see which one penetrates more.

His studies were done using highly inefficient bow/material design, thus the reason he pushes the weight factor. You can reach those momentum numbers via speed. The only difference between a light fast arrow and a heavy slow arrow is momentum decreases faster at long ranges with a lighter arrow. With in 60yards that's not an issue with todays speeds, even more so under 30yards. Hence the very few mfgs making plus 14gr per inch arrows.


You stated sub 500gr arrows with High foc lack durability.. that is incorrect. I get the pleasure of bow hunting year round down here and get to take 10-20 animals a year. Ranging from 60lbs to 900. I have no issues with passtrus or durability.

Ashby studies are very relevant, you just have to take them in to context correctly. Like don't use a big cutting diameter broadhead on light and slow arrows or longer ranges. In other words use a 1 1/8 coc head instead of 2" cut head or ulmer edge instead of rage extreme.

 

[tipsntails7]

You have to try really hard to get a 500gr arrow plus theses days. Point was more isn't always better hence no 2k gr arrows


You asked why KE was relevant in penetration, and I explained it. Its nothing more than measure of how efficient bow design is. Higher the efficiently higher the speed per poundage

Ashby's studies where based off momentum thus the reason he suggest momentum numbers for different animals.

His studies were done using highly inefficient bow/material design, thus the reason he pushes the weight factor. You can reach those momentum numbers via speed. The only difference between a light fast arrow and a heavy slow arrow is momentum decreases faster at long ranges with a lighter arrow. With in 60yards that's not an issue with todays speeds. Hence the very mfgs making plus 14gr per inch arrows.


You stated sub 500gr arrows with High foc lack durability.. that is incorrect. I get the pleasure of bow hunting year round down here and get to take 10-20 animals a year. Ranging from 60lbs to 900. I have no issues with passtrus or durability

Ke is technically not relevant to penetration because it has no directionality. it is stored energy being expended. momentum in itself his directional force. using the same bow but a heavier arrow traveling slower will have more momentum thus more penetration. read this, actual extensive field testing done by an archer with modern day equipment.

http://archeryreport.com/2012/01/kinetic-energy-momentum-arrows-simplified-approach/

 

[cuerro viejo]

You still not getting what I'm saying. You're focused on the "KE", not what's a product of a higher KE number associated with a bow and arrow set up.

You are also ignoring fact I can get to the same momentuem numbers ashby recommends of African animals with a lighter arrow at higher speeds.

Getting to the highest momentuem numbers possible with any set up is like me saying I use a 100lb draw. You're going to say good for you but why?


There are trade offs in everything we do especially archery. If I'm shooting a giraffe that's hide is over an inch thick and i can exceed ashbys recommended momentum numbers ya it make sense to get my weight up there, but an elk isn't a giraffe or one ton cape buff, nor is a pronghorn, sheep, mulie WT etc.

Ill take my one pin to 40 over three anyday in North America.

 

[tipsntails7]

Shoot what you want and have fun

 

[MattB]

You asked why KE was relevant in penetration, and I explained it. Its nothing more than measure of how efficient bow design is. Higher the efficiently higher the speed per poundage

Your explanation sounds a lot like KE doesn't have relevance to penetration (but rather to bow efficiency), which is the conclusion Ashby came to.

Ashby's studies where based off momentum thus the reason he suggest momentum numbers for different animals. If you don't think speed is relevant in penetration I don't know how to change you mind other than shoot same arrow weight at different speeds and see which one penetrates more.

Ashby's studies weren't based on anything per se, but what they determined was that KE did not correlate to penetration whereas momentum did. Ashby suggested that speed was not very relevant in penetration, whereas arrow weight had a very direct correlation.

His studies were done using highly inefficient bow/material design, thus the reason he pushes the weight factor. You can reach those momentum numbers via speed. The only difference between a light fast arrow and a heavy slow arrow is momentum decreases faster at long ranges with a lighter arrow. With in 60yards that's not an issue with todays speeds, even more so under 30yards. Hence the very few mfgs making plus 14gr per inch arrows.

His studies didn't account for bow design, they measure arrow performance. The study also indicated that arrow weight was a better predictor than momentum, because regardless of speed an arrow of ~650 grs. achieved a threshold of heavy bone penetration whereas there was no such indication that achieving momentum of x had such an effect.

You stated sub 500gr arrows with High foc lack durability.. that is incorrect. I get the pleasure of bow hunting year round down here and get to take 10-20 animals a year. Ranging from 60lbs to 900. I have no issues with passtrus or durability.

Where did I state that? I believe you are misrepresenting my comments.

Ashby studies are very relevant, you just have to take them in to context correctly.

That is an interesting comment given you have contradicted a number of his key conclusions which implies the opposite.

 

[cuerro viejo]

KE shows the efficiency in which energy is transfered to the arrow.

High KE means higher velocity hence its velocity being squared.

Ashby did not say speed/velocity was not relevant in penetration. You can't have momentum with out velocity greater then zero. .. you see the correlation now " velocity"

His studies show higher momentum caused deeper penetration and heavier arrows retained speed at longer distances better. 600gr arrow at 300fts with out penetrate 600gr arrow at 200fts with the same head of course.

Ashby simply stated that you can still get good penetration with out speed by increasing weight and foc. But there is a point where you go backwards, there is also a point where you exceed what you need, and in doing so loose something else.

I havent contradicted any thing. You said KE wasn't part of penetration and i said it was a good indicator. Higher the KE the higher your velocity will be and higher your momentum will be with a given weight. His studies are relevant especially in the broadhead studies... if you have a low velocity and low momentum don't use a broad that has a massive cutting diameter. Once you get pasted a certian momentum use what ever you want

Smaller the broad head cutting area less momentum required


As far as durability, you said below

"The point I was trying to make is that in order to get a sub-500 gr. high FOC arrow one would have to use a pretty stiff/light shaft, and in doing so would give up durability"

Durability is not the product of weight its the product of materials and design. I don't know what your definition of durability is but it must be up there... above 99% of the arrows on the market

If thats the case 99% of the arrows on the market aren't durable(vast majority are are sub 10-11grs an inch) You can add high foc(by cert or added weight) to an arrow using the same spine number by simply cutting your arrows shorter(thus increasing its spine). Only expectation I can think of pushing the 500gr mark is if you are a long 30" plus draw, but even then your going to have to cut your arrows shorter do to your maxed on most spine charts and your going to have to cut back some .
anyway.

650gr means nothing in the the US or compound world. The Dr. never used a bow in his studies with an ibo over 330. On top of that nothing in north america has a scapula like a cape or water buffalo.

You want to break or piercing the scapula in North America pick a broadhead design with a smaller cutting diameter. Like a Solid, GK, helix etc.

Dr Ashby studies showed archery is compromise to it finest degree. You can shoot to light of an arrow just like you can use to heavy of an arrow.

650gr to hunt in whitetails, elk, moose, pronghorn mulies, pigs and exotics?. .you need to get release happy and go kill more stuff

High FOC sub or mid 400gr arrow over 300fts combined with a simple 1 1/8 cut head will pierce any scapula in North America, especially mid to upper scapula

 

[elkeaterco]

I was running the Rampage arrows with the 56gr bone crusher inserts. Loved them, crazy penetration, but too costly for my poor ass. I just bought 2 dozen of the Outlaws with the brass inserts and have to say they shoot as good for half the price. 28.5", 70lb, 440gr arrow, 14% FOC.

 

[cuerro viejo]

Those outlaws are probably the best sub $90 a dozen arrows on the market

 

[MattB]

His studies show higher momentum caused deeper penetration and heavier arrows retained speed at longer distances better.

Your first point can be situationally correct, but Ashby went to great lengths to highlight instances where less momentum from a heavier arrow yields better penetration than more momentum from a lighter arrow. I don’t believe your second point is referenced anywhere in the study.

I havent contradicted any thing. You said KE wasn't part of penetration and i said it was a good indicator."

Actually, it was Ashby that said KE does not show a positive correlation with penetration and your statement contradicts his findings.

Here is one quote as evidence of this

"Among actual outcomes, kinetic energy has failed to show positive correlation with tissue penetration. It is not useful as either predictor or predictive function."

Here is the source, p. 5:

www.tuffhead.com/ashby_pdfs/ashby ours/2007 Update, Part 1.pdf

There is also a good chart on the top of p. 6 here that shows instances of negative correlation between KE and penetration, and a positive correlation between arrow mass and penetration.

http://www.tuffhead.com/ashby_pdfs/ashby ours/2005 Part 4 Update.pdf

if you have a low velocity and low momentum don't use a broad that has a massive cutting diameter. Once you get pasted a certian momentum use what ever you want

Smaller the broad head cutting area less momentum required

That is far from what the study represented, it isn't even funny.

Here are some comments he made on broadheads:

9. All multiblade broadheads offer insufficient penetration when heavy bone is encountered.

10. Single blade broadheads penetrate significantly better than multiblade broadheads in both soft and hard animal tissue.

17. No multiblade broadhead can reasonably be expected to penetrate even a deer size animal when the hit is from the forward quartering angle and in the area of the neck-shoulder junction.

18. The most important factor in achieving adequate penetration is a well constructed single blade broadhead.

That doesn't sound like "use what ever you want" to me.

650gr means nothing in the the US or compound world. The Dr. never used a bow in his studies with an ibo over 330. On top of that nothing in north america has a scapula like a cape or water buffalo.

What bow he used was irrelevant, as the study was on the effect of the arrow on penetration. He did indicate that he tested arrows with velocities up to 325 fps (which I can assure you he did not achieve from a longbow), so the notion that this is a trad-bow only study is not accurate. The relative efficiency of longbows and compounds become much more similar with arrows in the gpi range Ashby recommends. But just to provide additional evidence that your assertions contradict Ashby’s findings:

“The second most important factor in achieving adequate penetration is adequate arrow mass (a minimum mass of 650 grains is recommended for 'standard' big game animals and 900 grains for 'super size' game).“

http://www.tuffhead.com/ashby_pdfs/ashby ours/PDF Arrow Lethality 4.pdf

The 650 grs. referenced approximates the lower bound for what Ashby describes as the "Heavy Bone Threshold".

Ashby wrote:

“For a given broadhead and shaft setup, arrow weight is the dominant factor in bone-breaching. That's because the arrow's weight significantly lengthens the time of impulse. The heavier an object in motion is, the longer it takes for a given resistance force to stop its forward movement.

Momentum (force) is mass multiplied by velocity, but not all arrow momentum has equal effect on the Heavy Bone Threshold. How the arrow attains its momentum is important. A substantial increase in the momentum of a below-threshold arrow, achieved through increased arrow velocity, shows little effect on the Heavy Bone Threshold. Increasing arrow mass to above-threshold value has a pronounced effect on the Heavy Bone Threshold, even when total momentum is reduced - such as when comparing arrows of like external dimensions from both a heavy and light draw weight bow. Why? Velocity is shed rapidly during penetration(and as the bone recoils and flexes) but arrow mass remains constant throughout the course of penetration, regardless of the resistance encountered.”

Simply put, arrow weight is a better predictor of heavy bone penetration and an arrow that generates more momentum through higher velocity and lower arrow mass may actually reduce penetration. Unless you are suggesting different laws of physics apply in North America than in Africa or Australia, I believe that your assertion that the ~650 gr. threshold is meaningless is yet another contradiction of Ashby’s findings.

As I suggested with my first post on this thread, there appear to be a lot of folks who pick and choose what they want from Ashby’s work, and some folks purport conclusions from his work that seem totally contrary to what Ashby himself has put to print. I just don't understand why folks would profess such faith in his work only to ignore the majority of his findings.

 

[Coyote Commander]

17. No multiblade broadhead can reasonably be expected to penetrate even a deer size animal when the hit is from the forward quartering angle and in the area of the neck-shoulder junction.

.

Well ive proven this one wrong on several occasions (more than id like to admit). Ive got a double exit on whitetails. Jumped the string, hit him quartering to in the shoulder, came out the other side, and re-entered in the stifle area due to the location at the time of his offside rear leg. Exited there too and stuck in the dirt. Several others ive blown clean through both shoulders (lots of bone in and out), and still others hit with a quartering to angle, and I can guarantee you I wasnt shooting anything near a 650 grain arrow. Ive been confident enough, and have put enough deer down with my rig over the last dozen years where there is literally not a bone on their body im afraid of. I completely destroyed a moose humerus on a deflected shot. Granted, I didnt have an exit, but I got penetration through the vitals after smashing it into over 50 pieces. Now, I know my first hand experiences arent a huge data set, but enough for me to say that though Ashby did some excellent work, he also made some pretty broad generalizations with no data to back them up.

While I agree with Ashby a single blade broadhead will generally out penetrate a multi blade design, ive also seen a STRONG correlation between a smaller head out penetrating a larger one. Much for the same reason a single generally out penetrates a multi.

Ill also take to the grave with me that a COC out penetrates a chisel point when bone is involved. Shot to many critters with each to think otherwise.

There are a lot of factors involved in penetration that Ashby didnt, or only briefly touched on.




I think we can all agree though, that a heavier arrow pushed as hard as you can push it, is a killer, and if you can incorporate high FOC into that system, you have an arrow that groups well, and stabilizes broadheads better. And that once an acceptable momentum threshold is hit for the intended game, it may behoove one to not go ridiculously overboard in any one department and strive for as flat shooting a "heavy" arrow they can get and find that good compromise.

I dont want to give up arrow weight to chase a flat trajectory. Neither do I want to give up more trajectory than I have to in chasing an ultra heavy arrow. I want to find that balance for the intended game ill be hunting. And in N. America, other than maybe grizz, I just dont see the need for a 650+ grain arrow out of a modern compound bow. Maybe some day my tune may change, but ive killed hundreds of animals with a bow, from moose down to rabbits and a lot in-between with what Ashby would call a "light" arrow and what most in this Country would call a "heavy" arrow.

 

[Coyote Commander]

Those outlaws are probably the best sub $90 a dozen arrows on the market

I would say all of their shafts are pretty damn reasonable compared to the "big name" arrow companies.

If these are good arrows, I may be ditching the name brand shafts.

 

[5MilesBack]

I was running the Rampage arrows with the 56gr bone crusher inserts. Loved them, crazy penetration, but too costly for my poor ass.

What happened to them, did you get rid of them?

 

[elkeaterco]

What happened to them, did you get rid of them?

Going on a DIY Caribou hunt and only had 8 left (used shit glue(platinum) and lost a couple inserts and broke one). 8 would probably be more then enough but wanted to take at least a dozen (just in case). Figured why buy one dozen when I could get two for the same price. I just shot one through a fence and through a metal pole. It's in perfect shape still. Been shooting them out past 80 yards with good results.

 

[Zbowman1]

This was one of the best threads I have read on Rokslide to date. Valid points on both sides. Gives a guy a lot to think about. Thanks to all that contributed.

 

[elkeaterco]

Finally got around to getting that arrow out today. I unscrewed the field point and she came right out. It had some minor cosmetic scratches and passed the spin test.

View attachment 17127
View attachment 17128