DAS Bows-How is it possible

[Bowhunter4life]

http://kineticbows.com/gallery/Safari-Room

Hey Ron, that is a link to the pics in the DAS "Safari-Room".  Doug's pics are right there on the first page.  The poundage was 66# (don't know the draw length) and 850 grain arrow for two and a 935 for another.

[bayoulongbowman]

Think about shooting a pig Boar H_O-G-G...with DAS...wow!!!!!!!!

[Bill Carlsen]

I feel I need to add my 2 cents here. I am not a buff hunter and never will be. But about a year an a half ago my wife told me she wanted to hunt...and she wanted to start off killing a black bear. (Long story here). So I decided that since she only shot a bow in the mid forties at her 26"draw length I needed to find the best performing recurve I could find. It so happened that there was a lot of chatter on some website about the new DAS bow (anoher long story here) so I decided, after talking to Dave Soza, that he seemed to know what he was talking about and ordered her the bow. It was about 50# when we got it (too much for her) but the thing actually out shot my 66-69# recurves...all top shooters. After some fooling around with her draw weight we settled on 46# and a 500 grain Beman MFX shaft (total arrow weight) and she shot completely thru a mature black bear that first season. I also own a DAS bow, 60#, and in my 55 years of shooting feel that it is the best performing hunting bow I have ever shot. It is fast, quiet and extremely accurate. If I were to become a buff hunter then the DAS would be going with me, as is, with some heavier arrows than I currently shoot. I don't know all the physics of how the bow does what it does, but it does. What Doug Chase did with his on the buff hunt just can't be argued with, unless there is another agenda going on. It's the best damned hunting bow on the market.

[Ray Hammond]

Ron,

You still need to be aware that a heavier arrow will provide greater momentum downrange matched up with ANY bow...so adding arrow weight WILL improve penetration..and that is what you are asking about, I believe.

Those discussing it above were offering you information that would assist with whatever bow you end up taking..DAS or otherwise.

Think of it as a free lunch- whatever bow you select, if you ADD arrow weight its LIKE adding poundage to the limbs.

You do not have to double arrow weight to see the benefit, either. In speaking with Ed Ashby on Saturday morning it was apparent that there is a threshold of between 625 and 650 grains that once reached and beyond bone BREAKING and penetration occurs with a great deal more frequency, especially with double tanto tipped grizzly's.

Weights of 650 to 850 are what I regularly shoot and complete penetration of hog shoulders is a regular thing with arrows of these weights-obviously you would NOT shoot for shoulders on larger game like elk, moose, or buffalo, but you have a much greater chance of getting through enough arrow to do lethal damage to a critter that big than one would below that 625 threshhold if an error is made and you place the arrow where it will hit those bones.

[Ghostman]

I'm not a DAS hater or basher but it seems the more DAS bows are talked about the more rumors and unrealistic claims grow.

A DAS with W&W WinEx limbs will not shoot hunting weight arrows much if any faster than a comparable weight high quality custom bow like a FF Silvertip, ACS CX, Centaur double carbon, Black Swan, Palmer double carbon Morrison Cheyenne or a couple of other fast bows. WinEx limbs will pull much smoother than the average wood core limb bow and will shoot light weight 6 gpi carbons better but who hunts with arrows that light?

For those who think this statement is BS ask David or better yet do some chronographing and side by side comparrisons for yourself.

The DAS is a great bow with tremendous adjustability and tunability but to claim that it shoots faster than comparable custom recurve bows 15-20 lbs heavier simply is not true.

[chuckbowhunter]

Hey Ghostman,

You are right on the money and I say that as a new DAS owner.  I bought the DAS because I wanted a high performance bow and all the other brands you listed had a year or longer wait.  Now the DAS does blow my Hoyt Tiburon away however after converting the Hoyt to DAS ILF limbs there isn't that much difference.  The real advantage of the DAS is the tunibility that I don't see in the other bows.  You can still get to the same place but it will cost you a few dozen arrows finding the right solution.

[Ron Chambers]

Kinda what I thought. I will build a bow for the hunt and add weight to my arrows.

[Dr. Ed Ashby]

Don't get hung up on bow draw weight, or even the specific bow you prefer to use. There are too many much more important factors. For the last several years I've been using arrow impact momentum as the reference point for the studies. Bow efficiency differs greatly, and your draw length (the power stroke) is an important factor in how much momentum you will get with a given bow/arrow setup. I have a short draw (27") and need a heavier draw AT A GIVEN BOW'S EFFICIENCY LEVEL to get the same momentum with the exact same arrow as someone with a longer draw. Having said that, there is no such thing as too much bow for truly big game, regardless of your draw length. Use all the bow you CAN HANDLE.

The second point is that it is the arrow which actually does the killing. By using an arrow of high penetration potential you can get more terminal performance (outcome penetration) from a lighter draw bow than you will from a much heavier draw bow OF THE SAME EFFICIENCY using an arrow with poor penetration potential. That's why the study data is set up as it is. If you maxamize arrow performance from a given bow you can chronograph your setup, calculate the momentum, and get a fair idea of the likely outcome penetration under verious scenarios.

With a given bow, a heavier arrow will always show higher momentum than a light arrow of equal physical dimensions. Use as much arrow mass as you can while maintaining trajectory adequate for the ranges you shoot. The study does clearly indicate the presence of a heavy bone threshold, and it's wise to maintain arrow mass to at least 650 grains, just in case of a heavy bone hit. But also remember that arrow mass is just one arrow penetration factor. At any given level of arrow mass, a lot of other things can be done to increase penetration potential.

Every early test indicates that FOC is going to turn out to be a major penetration factor, and I hope to have a lot more information on THE DEGREE of its effect after this year's testing. One of the FOC test I have planned is with extreme FOC arrows from a light bow. This is using a recurve with adjustable poundage, from 40 to 55 pounds. I'm just curious what penetration I can get with the best arrow I can devise from such bow weights on a buff. Should be interesting.

A bow is just the launching platform. It's the arrow that must perform, and more terminal performance can be gained through arrow design than through bow weight or performance. In testing, poorly designed arrows kill terminal performance. A poorly designed arrow won't even get through a buff's ribs with regularity, even when driven from a compound at 325 fps, putting out 94 ft.-lbs. of kinetic energy and .70 slug-feet/sec. of momentum!

Ed

[Torben Jensen]

Ghostman are you referring to my post on page 1 in this thread ? If you are please explain which part you don't believe.
Torben (TCJ)

[schlaggerman]

I own Black Widows and a DAS Custom with WinX limbs, most of my bows are in the mid 50's in bow weight. I cannot see any appreciable difference in bow performance in my Widows and DAS, as far as speed is concerned. Obviously the DAS has more adjustability to obtain perfect arrow flight. I've never had any problem getting perfect arrow flight out of my Widows though either and I'm talking bare shafting, even with broadheads on. The perceived advantage of the DAS is getting perfect arrow flight which will always increase penetration. The DAS is a very stable shooter however, and very accurate. I believe I can shoot tighter groups with my DAS. Here's my opinion why. The DAS limbs have less recurve than the Widows and hence seem to have less shock or jump upon release. The DAS WinX limbs achieve similar speed to the Widows because the limbs are constructed of foam and carbon, no wood laminations thus making the limbs lighter in physical weight. Will a DAS outperform a 15lb. heavier Widow, I don't think it would even come close assuming you are able to tune your Widow to shoot your bare shaft arrows perfectly with broadheads on. With todays carbon arrows and all the weight adjustments you can make on those carbon arrows this has never been a problem for me. I can get fletched field points, bare shaft field points, and bare shaft broadheads all to fly to the same grouping without any waver in flight. That's what you need to achieve. Now perhaps for some people that is easier to do with the great adjustablilty of the DAS.

[chuckbowhunter]

Dr Ed,

Have you done any research on a small diameter shaft vs. a larger diameter shaft for penetration?  As a shooter of Beman and Axis shafts I believe they penetrate better but that is just a totally unscientific guess based on how they performed on animals.  At the same weight will a small diameter arrow penetrate better?  Thank you for sharing all your great research.

[Torben Jensen]

Schlaggerman Im not saying it will outshoot a widow with 15 pounds - please go back and see what I wrote.
In essence this is what I get :
With midweight hunting arrows  (550-650grains) the difference is 7-8 fps with Winex limbs. That again is something like 4-6 pounds of draw.
When i go to very heavy arrows (13grains/pound) the Winex still have app. the samme performance gain over the widow in fps. Now it comes : going to Samick Masters limbs and 13grains/pound the difference between my widow and DAS/Samick grows to 13-14 fps. That is something like 7-9 pounds which I think is much. The Samick limbs at midweight hunting arrows shoots app. like the winex so they only "shine" going to the very heavy ones.
The testing was done the following way :
12 strand dyna with 4 widow spider silencers on both bows. The drawweight was measured with the same scale and an arrow of excact 13grains/pound was made for each bow. The arrow was weighed on a electronic powder scale. Both grips are exactly 1,75 inches thick (AMO standard) from bottom of grip to backside of bow at the shelf.
Because of that my partner could use a mark on the arrow to check relative to the bow that I drew the same length on both bows. Most of my shots had from 0-1 fps variation from shot to shot. I went back and forth between the bows alternating the shots. The only thing that was different was the braceheight. The DAS was 7,5" and the widow was 8,0". I tried one shot with the widow at 7,5" but it felt and sounded horrible (BW don't rec. going under 8") so I didn't do it anymore. Anyway I wanted to compare the bows under the circumstances I was going to shoot them in "real life" hunting.
As a last comment : I don't have a horse in this race - and if I had it would have been for the BW because I have shot/owned more than 20 of their bows over the last app. 18 years and I love these bows. But in 3 month time I stand in front of a Buff in Darwin and then I want to shoot what is most efficient for that.
Please feel free to tell me if I could have done anything different to make the comparison more fair.
Torben

[Dr. Ed Ashby]

Hello Chuck,

All I can document on the penetration effects shaft diameter so far is the following.

When all other parameters are held constant: BH, quality of arrow flight, shaft material, mass weight, % FOC, shaft design (for example, all shafts being parallel, or all being tapered or all barrel tapered shafts) shaft finish, impact force, relative size of test animal, and the nature and angle of tissue hits):

(1) When shaft diameter is larger than the diameter of the BH's ferrule penetration DECREASES by an average of 30% when compared to the penetration of a shaft having a diameter that equals the BH's ferrule.

(2) When shaft diameter is 5 to 8 percent smaller than the BH's ferrule diameter average penetration INCREASES by an average of 10% compared to a shaft having a diameter that equals the BH's ferrule.

This equates to a 40% difference in average penetration when comparing a shaft with a diameter larger than the BH's ferrule to a shaft with a diameter 5% to 8% smaller than the BH ferrule diameter. That's a very significant difference, making shaft diameter one of the high priority design features in reducing resistance to penetration. It is obvious that the BIG mistake would be to use a shaft diameter larger than the BH's ferrule diameter.

Thus far I've not been able to document an average penetration difference between shafts 5 to 8 percent smaller than the BH ferrule diameter and those with a greater difference between the shaft and ferrule diameters.

There's no reason not to go as small as you would like in shaft diameter, and it certainly does not hurt to do so, just keep them at least 5% to 8% smaller than your BH's ferrule diameter. Hope that helps answer your question.

Ed

[hormoan]

Hi Ed

     It was a pleasure to meet you at Larrys, keep up the good work.
 
 

 

I really liked your picture of the bull that had a thing with your block target!
 

Thanks for all you do for us.

             Brent

[Dr. Ed Ashby]

Hay there Brent! Glad to see the buff photo on the computer screen came out good. That old boy is one of my favorite pictures. Look at that concentration! That's what instinctive aiming is all about!

It was really imprssive to see what your long draw did on that light draw ACS-CX with those 780 grain arrows. Sure brings home how important power stroke is and why I need a lot of bow at my shorter draw! Makes me want to dust off a few of the really big bows when I get back to Oz!!!!

I'm headed back to GA tomorrow AM for the flight to Africa, but can hardly wait to get back from there and head off for the next round of Buff testing.

Ed

[hormoan]

Good luck Ed, and have a safe trip. We will all be waiting, for more reports!

                          Brent

[Dr. Ed Ashby]

Brent, whenever you get down for your buff hunt be sure to fill out a data sheet for me. If you hunt with Bill, he has some on hand. If you decide to hunt elsewhere just let me know and I'll email the field record sheet to you.

Ed

[Torben Jensen]

Hi Ed

I go to Darwin after buff at Andrew Mackays place (Hotspur Lodge) in June this year. If you want me to fill out a data sheet just email one to me. I can't guarantee there is something on it afterwards but I sure as heck will give it a try.
I have set up my arrows pretty much following the advice in your reports :
Thin shaft (Beeman Max 4 spine 300) with part of child carbon shaft glued inside in the middle part for adding stiffness. 100 grain brass point adapter. Grizzly El Grande with 100 grain steel adapter. Total weight 830 grains and Foc close to 24%.
Bareshafts perfect with a speed of 170 fps out of my DAS recurve at 65#.

I have been granted permission by my wife to go out and buy some of the lubricant you talked about earlier today (LOL) - but I don't know how to use it. I mean on the arrows ! Do you put on a thin coat and let it dry or do you need a heavy coat or what ?

Also I am a little in doubt if I remember correct to use right wing feathers with the grizzly broadhead ?

Thanks for your help and I look forward to seeing the rest of your work.

Torben

[schlaggerman]

Hi Torben, Wasn't trying to dispute your findings, I was just responding to the original question. I hadn't even read your response. Our limbs and arrows are different anyway and a direct comparison probably can't be considered. I have WinEx limbs and you have Samick, plus you are shooting heavier arrows. My arrows are 500gr., about 9gr. per pound of bow weight. With my combination the DAS is not faster than the Widow. The DAS limbs very well may stand out more when heavier arrow to bow weight ratios are achieved. I just don't believe there could ever be a 15lb. make up in performance as was posed in the original question.

[Torben Jensen]

Hi Schlaggerman, no problem. I agree with your statement of 15 lb between a DAS and a widow is not possible.
I'm bringing up a possible reason why you don't see the same difference of 7-8 fps between your widow and the DAS/winex combination that I get. I'm sure you already are aware of it but I will mention it anyway : How efficient the DAS/Winex limbs are depends a lot on the amount of preload you have your bow setup to. The combination of the bows length, your drawlength and how far you have cranked the limbs in or out does a world of difference. If you have a short to average drawlength and maybe have the long or medium limbs and combined with the limbs is on their lowest weight setting (cranked out)you will get relative poor performance. On the other hand if you have a long draw and short to medium limbs cranked all the way in you will also get poor performance plus you risk damaging the limbs.
Somwhere between these variables the bow has a "sweet range" where it is very efficient.
David has done a ton of testing to find out the right combinations so he can help you out if you haven't set it up at its best setting yet. Or you can bring out the cronograph and see for yourself. Another way to put it : say a guy wants to shoot 50#. He can do that in many ways.
For example he can use "light" limbs bottomed out or he can use "heavy" limbs cranked all the way out. Both bows are the same poundage but the performance you will get from them is very different.