DR ASHBY ON LOW POUNDAGE BOWS ?

[O.L. Adcock]

Tom, He might be but the context of the Doc's work is optimizing the bow you have in your hand. Of course a heavier bow with the same arrow will penetrate better but not as good as if you increased it's mass to the same gr/lb.

SuperK, I found that article, Aug/Sep 2008 TBM, the fellows name is Ron Kulas. His test was similar to yours with a homemade 45# bow shooting a 450gr arrow at 142fps from 10 yards. A hit a couple inches above the shoulder/leg joint resulted in the shoulder blade being completely split and the arrow penetrated to the fletching. You'd think with the less arrow mass that would not have happened. He doesn't say what his FOC is but he was using 170gr Grizzly heads on a POC shaft. I'd guess he was at least 15-18% with that set up.

The FOC factor...It basically shattered all the work Doc Ashby had done years ago in the Natal studies. High FOC's will penetrate as well or better than "normal" FOC that are MUCH heavier. I like arrow mass but only if I can put it in the front end!   ....O.L.

[Ray Hammond]

the difficulty with that, Tom, is that the same arrow more than likely will NOT be perfectly tuned for BOTH of those bows.

Something will have to likely change- point weight, shaft length, something.

Adding speed should be the last thing we worry about.

At twenty yards and under the performance advantage of adding 10 or 15 feet per second is INCHES of difference in reaching the target.

Besides, momentum is the key to penetration. The resistance to stopping is what we need to be concerned with.

O L Adcock laid down the 9( I can't count too well, but I think that was how many he wrote above) commandments

And arrow placement is the single most important factor in any hunting situation no matter what any of us say: If you put the arrow in the right spot, you can shoot field points.

Unfortunately, after watching a great many trad shooters loose arrows at game, including myself, I am of the opinion that we MUST set up our equipment prepared for the worst possible outcome, and practice like crazy to make the PERFECT SHOT. You can tell us how great a shot you are, and how you have never wounded and lost game all you wish. I'm not certain we are being as honest with ourselves as we should be if that is the tack we are taking.

In preparing this way, and should we have a less than perfect hit, and often when that happens we strike bone, we stand a good chance of breaking that bone, and getting into tissue that can kill the animal.

If on the other hand, you only hit soft tissue, I also want a single bevel head that is spinning through that tissue, to do the most possible damage while its traveling through the animal.

In the final analysis, the original questioner seemed absolutely befuddled by this whole situation and has threatened to stop hunting over it.

In my opinion, you should get some arrows together, and go hunt a hog. If you see a hog that you think is too big for your setup, here's a thought- DON'T shoot it. Move on and shoot the next one. You'll do just fine.

[Sharpster]

RonD,

There's a FOC calculator in the How To/Resorces forum. Here's the link:

  http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000089

Ron

[trashwood]

O L - Didn't mean to seem I was making negative commmets regrading the research but in most case it is looking at exactly the wrong end of the hunting shot to make clean kills.  The emphasis
should be place on the accuracy of the shooter.  

if all the trad bowhunters could hold all the 4" to 5" groups at 20yds we talking about, they would be at the National Indoors collecting 1000 of dollars.  How many trad bowhunters do you know that can put 60 arrows in a 5" group at 20 yds????

while the Dr's research is remarkable and intersting, it does not equal clean kills accruacy does

rusty

[trashwood]

I take that back.  the research does not put the emphasis on the wrong end of the shot, we are.  the research is neutral, we aren't

rusty

[TomMcDonald]

Originally posted by O.L. Adcock:
Tom, He might be but the context of the Doc's work is optimizing the bow you have in your hand. Of course a heavier bow with the same arrow will penetrate better but not as good as if you increased it's mass to the same gr/lb.

SuperK, I found that article, Aug/Sep 2008 TBM, the fellows name is Ron Kulas. His test was similar to yours with a homemade 45# bow shooting a 450gr arrow at 142fps from 10 yards. A hit a couple inches above the shoulder/leg joint resulted in the shoulder blade being completely split and the arrow penetrated to the fletching. You'd think with the less arrow mass that would not have happened. He doesn't say what his FOC is but he was using 170gr Grizzly heads on a POC shaft. I'd guess he was at least 15-18% with that set up.

The FOC factor...It basically shattered all the work Doc Ashby had done years ago in the Natal studies. High FOC's will penetrate as well or better than "normal" FOC that are MUCH heavier. I like arrow mass but only if I can put it in the front end!    ....O.L.

I understand O.L. I was just making sure I understood what he meant.

[TomMcDonald]

Originally posted by Ray Hammond:
the difficulty with that, Tom, is that the same arrow more than likely will NOT be perfectly tuned for BOTH of those bows.

Something will have to likely change- point weight, shaft length, something.

Adding speed should be the last thing we worry about.

At twenty yards and under the performance advantage of adding 10 or 15 feet per second is INCHES of difference in reaching the target.

Besides, momentum is the key to penetration. The resistance to stopping is what we need to be concerned with.

O L Adcock laid down the 9( I can't count too well, but I think that was how many he wrote above) commandments

And arrow placement is the single most important factor in any hunting situation no matter what any of us say: If you put the arrow in the right spot, you can shoot field points.

Unfortunately, after watching a great many trad shooters loose arrows at game, including myself, I am of the opinion that we MUST set up our equipment prepared for the worst possible outcome, and practice like crazy to make the PERFECT SHOT. You can tell us how great a shot you are, and how you have never wounded and lost game all you wish. I'm not certain we are being as honest with ourselves as we should be if that is the tack we are taking.

In preparing this way, and should we have a less than perfect hit, and often when that happens we strike bone, we stand a good chance of breaking that bone, and getting into tissue that can kill the animal.

If on the other hand, you only hit soft tissue, I also want a single bevel head that is spinning through that tissue, to do the most possible damage while its traveling through the animal.

In the final analysis, the original questioner seemed absolutely befuddled by this whole situation and has threatened to stop hunting over it.

In my opinion, you should get some arrows together, and go hunt a hog. If you see a hog that you think is too big for your setup, here's a thought- DON'T shoot it. Move on and shoot the next one. You'll do just fine.

Ray. I just basically meant all things being equal, the same arrow will penetrate more if it's going 50fps faster. I wasn't delving into spine weight territory.

[O.L. Adcock]

No problem Rusty...Accuracy is like tuning, it should go without saying...While the effects of this other stuff isn't so apparent. We could all practice more and that won't hurt!    The FOC part does tend to tighten groups....O.L.

[BLACK WOLF]

Originally posted by TomMcDonald:
All things being equal. I took that as this:
The same arrow (same weight, same tip weight, etc...) shot from a 40lb bow and then from a 50lb bow (of the same performance in their respective weights).
The faster the arrow is travelling the more it will penetrate (a hit on the same spot with the same sharpness in the blade).
Is this what you were getting at Ray?

Originally posted by O.L. Adcock:
Tom, He might be but the context of the Doc's work is optimizing the bow you have in your hand. Of course a heavier bow with the same arrow will penetrate better but not as good as if you increased it's mass to the same gr/lb.

Exactly Tom...which is why I stated all things being equal in regards to the 2 arrows.

I wasn't trying to speak in context of Dr. Ashby. I was just clearly trying to state a fact of physics.

The arrows are the same diameter, same weight, same material, same broadhead, tuned perfectly, same FOC, etc., etc. so when comparing the 2 arrows the only thing that is different is one of them is going faster than the other.

The faster arrow will out penetrate the slower one within the parameters I laid out....anyone who tells you differently is wrong. BOTH KE and M will be higher with the faster arrow in the situation I was discussing.

Ray      

[BLACK WOLF]

It’s the same thing with testing FOC or any other differences between 2 arrows.

In order to have an accurate test…you need to eliminate as many of the differences between the arrows as you can to produce a more accurate comparison.

An arrow with higher FOC isn’t a guareentee that it will out penetrate an arrow with lesser FOC…especially if the arrow with higher FOC is way out of tune when compared to the other arrow.

But when you make sure all aspects between the arrows are equal and only change FOC...the outcome should be the arrow with higher FOC should out penetrate than one with lesser.

It's the same principle or testing guidlines as comparing the slow and fast arrow.

Ray  

[Sharpster]

[/qb][/QUOTE]Exactly Tom...which is why I stated all things being equal in regards to the 2 arrows.

I wasn't trying to speak in context of Dr. Ashby. I was just clearly trying to state a fact of physics.

The arrows are the same diameter, same weight, same material, same broadhead, tuned perfectly, same FOC, etc., etc. so when comparing the 2 arrows the only thing that is different is one of them is going faster than the other.

The faster arrow will out penetrate the slower one within the parameters I laid out....anyone who tells you differently is wrong. BOTH KE and M will be higher with the faster arrow in the situation I was discussing.

Ray          [/QB][/QUOTE]


Ray, If in your scenario the arrows are truely identical in every way, then I think only the K.E. would be increased by the faster arrow, not the mass.

The one point that has not realy been addressed is FOC in regards to the e=mc2 equation.

If the both arrows weigh the same, are well tuned, and shot from the same bow at the same speed but one arrow has a far greater foc than the other, the higher foc arrow will certainly get better penetration.

This seems to indicate that Einstein's theory may not be absolute? Hard to believe that a bunch of trad bowhunters could challenge a fundemental law of phyics but, is this not correct???   :confused:  

Ron

[BLACK WOLF]

Originally posted by Sharpster:
Ray, If in your scenario the arrows are truely identical in every way, then I think only the K.E. would be increased by the faster arrow, not the mass.
Ron

You're right. The arrows mass doesn't change...but it's speed does...and therefore it's Momentum changes.

When determining an arrow's Momentum...speed plays a factor in that...just not as much when tring to determine KE.

Maybe you understood M as Mass when I was using it to abbreviate Momentum???

Ray  

[Java Man]

Sharpster,

No change there to the e=mc^2 equation. Same energy, its just that the one with higher foc, uses its energy more effectively (work).  Therefore, we probably have not overcome any laws of physics.....yet!

Java Man

[Sharpster]

Yup Ray, That's how I mistakenly took it.

Java Man,... That's a bummer, thought that would have been cool.  

Ron

[novahunterpa]

I love these post's, and the info they provide.
I find it interisting that the work that DR. Ashby and others have done to advance our knowledge, funny how most of this has been done by individual bow hunter's and archers and not by the mulit-million dollar bow hunting industry, and maybe thats the way it should be.  Thank you all that have spent time and money testing hunting equipment.

Aslo for those that are using e=mc2 to figure arrow performanc, i belive this would be incorrect.  No need to use einstein physics when newtonian physiscs works just fine.  e=mc2 tels u noting about an arow in flight it would work for converting the entire mass of the arrow if converted into energy  e=mc2 (energy=massXthe speed of light squared)

[freefeet]

Doesn't the e in einstein's formula refer to nuclear energy?

As in the energy contained within an atom of helium is equal to the mass of the atom x speed of light squared.

I've never encountered having to use einstein's formula in mechanics ever.  As someone said, Newton's theories are what's relevant when dealing with mechanics.

At least that's the way i remember maths, physics and engineering lessons.

[Bjorn]

I don't know about all the physics; my young son has a 24" draw and shoots a 50# bow which generates 36-38# at his draw. We have worked on his arrows-5/16 cedar, heaviest and stiffest we can find. A surgically sharp, and I do mean sharp, STOS or Grizzly-145 grain (whichever is around).
The most efficient and quiet bow-with the arrows tuned to match-in our case an ACS CX. 10 strand dyneema string-anyway his set up has had a lot of work tuning, bareshafting and all the rest, on top of all this my son is a very, very good shot. He has killed hogs up to 100# and a sheep that was a little more than that. He knows to stay away from the bigger hogs; but as his power increases so will the size of his kills.
I guess what I am saying in a round about way is the lighter equipment can get the job done; but you really should do extra work on your tuning, shooting and stalking.

[kibok&ko]

Hello everybody, great topic, personally i'm shooting a 52 pounds recurve bow (very low poundage for France where people like big bow to hunt roedeer ..... )

My last arrow tuning is a 676 grs arrow (340 in front) ...

Something like 13grs / pounds

I've never been under 640 grs with this bow

very good results on Sanglier !!!!!!


Working very well

[O.L. Adcock]

Novahunterpa, "I find it interisting that the work that DR. Ashby and others have done to advance our knowledge, funny how most of this has been done by individual bow hunter's and archers and not by the mulit-million dollar bow hunting industry, and maybe thats the way it should be."

Yep...My experience with the big folks employing NS engineers, with testing capablities far beyond us shadetree wantabee's, and deep pockets aren't interested in anything other then the status quo. It's fun watching flight records set by the likes of Hoyt, WinWin, ect..fall to "longbows"...

Bjorn, We need to get him a good string on that thing and see how he likes it!   ....O.L.

[Bjorn]

I am all ears OL-what kind of string are you recommending for Adam?