Dr. Ashby Report Question

[Steve O]

I attended Dr. Ashby's presentation at Kalamazoo last weekend.  Lots  of good  information!

One thing he mentioned that I wanted to look up and read more about was his comment on arrow weight and penetration.

If I understood him correctly, he said   IF your arrow weighs over 650g and you are using a quality single bevel broadhead, you will penetrate a water buffalo (rib?) with a bow as low as 45#,   100% of the time.  I believe almost 20% of  his test shots were with a 43# or 45# recurve. He said it is extremely rare to have a 100# success rate in any field study, but this was the case.

I went to the Ashby Forum, but the amount of info there is substantial.  Does anyone remember what report this part of the study is in so I don't have to go thru them all?

[Mike Vines]

I too was there, and that was a huge amount of info to digest in that amount of time.  Yes you are correct in your figures you mentioned, atleast that is the same thing I remember hearing as well.  It opened my eyes quite a bit.  Wish I could help you further.

[smoke1953]

He also stressed for maximum penetration with at least 650 gr that it is important for the weight to be distributed FOC as much as possible and have the razor edge creating the lever action that only occurs with a single bevel design. That lever action creating the splitting effects on bone was something to see as well as the "starburst" effect through soft material with the exception of the lung material. I have never used single bevel however after seeing the live presentation I was convinced to give it a try. I did notice that they filmed the presentation and hopefully that will show up somewhere soon. I believe it is worth viewing.

[JimB]

The bow was a Bear Formula Silver,40# at his draw length of 27"
2008 Update Part I
  http://www.tradgang.com/ashby/2008update1.pdf
Part 2 compares those arrows from the 40# bow to "normal" arrows out of the heavier bows.Some pretty interesting stuff.
 http://www.tradgang.com/ashby/2008update2.pdf

[Steve O]

Thanks Jim!

[JimB]

That stuff is tough to wade through.If you go to tuffhead.com and go to their links on the reports,in addition to say,2008 Update,Part 2,it will give a short title also which doesn't tell you everything but it does help  sort them out a little.

Those are a couple interesting updates.I was always hoping he would do more work with the 40# bow,especially on deer sized game.

[Hud]

I seem to recall he advocated an FOC of 29%, or higher. Pretty hard to achieve on wood arrows. I plan to try out some footed, tapered woodies with 200 grains up front. It will be interesting to see, how much they drop over 20-30 yds, with my 66# and 70# longbows.

[Shakes.602]

Penetration is All Well and Good, but You have to get it in the  CORRECT SPOT  to do that kind of Damage, as I am sure you all are aware of. Happy Hunting Brothers!!  

[Troy Breeding]

Most, if not about all of the UEFOC arrows Ed or I have been able to get were carbon. This is mainly due to the light GPI found with carbon. Still, after picking up some of the woodie weights I feel EFOC can be obtained with wood. At this point in time I'm not sure UEFOC will ever be achieved with wood, but something in the high 20's looks possible. I'm going to try combining a 200gr woodie weight with a 225 or 300gr point and see what is possible with wood. It will be a heavy arrow for sure.

Troy

[YORNOC]

Be careful with the buff boys....numbers dont matter to an angry behemoth. Shoot as heavy as you can and have big bore backup if possible.
I've shot two bison, and they dont compare to the cape and water buff from what I'm told..
Dont skimp, dont cut corners. Listen to your guide.
I know this is more about penetration and single bevel stuff, I'd just hate to see anybody read this and say "oh yeah, 45# is plenty to kill buff" and think all is good and safe.    :eek:    

[Troy Breeding]

David,

Your right about making it understood that just because you have the setup that will handle heavy bone doesn't mean that anything walking is now in your kill zone.

I do my best to make it clear on this point. I promote heavy, high UEFOC arrows for helping when that "oh crap" shot happens.

From what Ed has told me he feels the use of heavy, high UEFOC arrows in light weight bows helps give that shooter the advantage when heavy bone is hit in normal size game.

I used to never hunt anything tougher than deer with a bow under 55#. Since moving up to heavy, high UEFOC arrows I feel I have a better than average chance of success on anything smaller than bison that walks in the US.

Troy

[calgarychef]

Listening to the guide is a good idea, especially if they have trad experience.  Their experience might not be worth a hill of beans if they have been guiding compounders shooting light arrows out of 80# bows.  In that case they wouldn't know that a 60 pound bow will work.

[Steve O]

Troy, I wish I could have stayed to see your part of the presentation, but needed to get back to my booth.  I am a big believer that momentum is more important than kinetic energy, and it was excellent to see that quantified in Dr. Ashby's graphs.

[SERGIO VENNERI]

What David and Tracy said!!

[YORNOC]

Originally posted by Troy Breeding:
David,

Your right about making it understood that just because you have the setup that will handle heavy bone doesn't mean that anything walking is now in your kill zone.

I do my best to make it clear on this point. I promote heavy, high UEFOC arrows for helping when that "oh crap" shot happens.

From what Ed has told me he feels the use of heavy, high UEFOC arrows in light weight bows helps give that shooter the advantage when heavy bone is hit in normal size game.

I used to never hunt anything tougher than deer with a bow under 55#. Since moving up to heavy, high UEFOC arrows I feel I have a better than average chance of success on anything smaller than bison that walks in the US.

Troy

I am with you Troy, and shoot FOC myself for everything. Devoured Ed's reports myself and love that the info is there for everyone. Just felt the need to add a bit of caution.  

[Steve O]

No worries here gents.  My hunting bows are all around 55 @ 28" and I draw 30"...

I got in touch with Todd Smith who was helping with the presentation to see if he could send me the videos that would not play.

They are on YouTube under Alaska Bowhunting.  Very interesting.


   Broadhead Testing

[Night Wing]

Looking at his figures based on a 43# bow with a 650 grain arrow, I wonder what the arrow drop in trajectory would be for any shot beyond 20 yards because that arrow is at least 15 GPP (grains per pound)?

I think arrow drop in trajectory would be quite noticeable at 25 yards and an eye opener at 30 yards with a 43# bow.

I don't have a PH.D in science, but I've got a PH.D in "common sense". Since I shoot a 42# bow, The heaviest arrow I've shot is 601 grains and I noticed the arrow drop in trajectory from 20 to 23 yards.

I did try shootng a 637 grain arrow and arrow drop trajectory wise, was like "throwing a brick from my hand" from 15 to 20 yards.

I don't care what degree(s) Dr Ashby has or how many. You won't catch me shooting 637 grain arrows or more grain weight out of my 42# recurve.

[Dr. Ed Ashby]

David and Troy are absolutely correct. While there are arrow setups that will breach the ribs on the Asian buffalo with a 100% frequency, even from very light draw weight bows, that DOES NOT mean that they are all fully adequate for sport hunting the Asian buffalo. Post-breaching penetration has to be considered.

For a setup to be 'adequate' for any big game it has to give complete thorax-traversing penetration AFTER breaching the entrance side ribs, from all rerasonable shooting angles. If you read through the reports you will find this stressed over and over. My best recommendation is to use the heaviest draw weight bow you can handle with arrow setups incorporating as many of the penetration enhancing factors as possible, and with as much arrrow weight as acceptable trajectory permits.

That said, there are arrow setups that will give a 100% breaching rate on the heavy bones of the Asian buffalo, even with a bow drawing as little as 40#@27". Those were all arrows with a weight above the heavy bone threshold with high-MA single-bevel broadheads. All were also in the EFOC/Ultra-EFOC range, but that's because those were the type of setups being tested in 2007-2008. The amount of FOC has NO EFFECT on the bone breaching rate but it does significantly enhance the amount of post-breaching penetration achieved. It would have been nice to be able to test Ultra-EFOC arrows from both the 54# and 40# bows, but probably won't get to do that one now.

You won't find the specific chart I presented at Kzoo in the updates. It showed a cumulation of the 2007-2008 testing to demonstarte that there are, indeed, true bone-breaking arrows; setups that can be relied upon to breach a heavy bone. With 169 consecutive shots breaching not only the entrance side ribs but also the scapula and spine on animals as sizable as these buffalo, even when bow draw-weight was very modest and the shooting angle was oblique, it's pretty difficult to maintain that 'no arrow is a bone-breaker', or 'no arrow can be relied upon to break a heavy bone'.

In an emergency situation, yes, I would take on those buffalo with that arrow setup and the 40# bow, and a good number of the shots would achieve lethal post-breaching penetration, but it definitely is not what one wants to sport hunt a buffalo with. There's a difference between 'can do' and 'will do' performance. Those arrows from the 40# bow demonstrated 'will do' bone-breaching performance on the buffalo, but it only showed 'can do' performance on post-breaching penetration. A good buffalo bow/arrow combination needs to show 'will do' performance on both.

Ed

[owlbait]

Thanks Dr. Ashby. We tried to get to your seminar but somehow missed it. Maybe there wasn't room for anyone else anyway. Thanks for your reports and the way you share the information. I hope those videos do become available.

[chopx2]

While not a buffalo, I shot a doe about 10 days ago with an UEFOC arrow having a 3:1 MA single bevel weighing in at about 660 grains from a 66# @ 29" LB. The arrow entered the neck cut through the neck vertebra at a 45 deg angle going forward and down. It took out the spinal cord split through the bone then took out the jugular vein on the way out and stuck into the ground on the far side. The arrow didn't even seem to slow down. Had the doe not dropped I would have thought I missed.

I'd like to see a coumpound guy try and achieve that with a 400gr Rage tipped arrow going 330fps.

That is why I shoot heavy UEFOC with single bevel. When I need to have no doubt when I doubt the spot of the hit.