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Main Boards => Dangerous Game => Topic started by: Dr. Ed Ashby on December 22, 2010, 12:56:00 AM

Title: How much penetration gain per 1% FOC increase?
Post by: Dr. Ed Ashby on December 22, 2010, 12:56:00 AM
How much penetration do you gain for every 1 percent increase in EFOC/Ultra-EFOC? If arrow FOC is increased how much can arrow weight be decreased without a loss in the amount of penetration? The 2008, Part 6 Update has what the Study data indicates. It was posted today. Here's the link.

 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=24;t=000021

Ed
Title: Re: How much penetration gain per 1% FOC increase?
Post by: BenBow on December 22, 2010, 12:21:00 PM
Perfect timing Ed. I've been given the opportunity to shoot a bison that is to be butchered.
Galen
Title: Re: How much penetration gain per 1% FOC increase?
Post by: tg2nd on December 22, 2010, 12:22:00 PM
Thanks for the data, Dr. Ed!
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Kris on December 22, 2010, 11:16:00 PM
As always, thanks for your excellent info!

Kris
Title: Re: How much penetration gain per 1% FOC increase?
Post by: kibok&ko on December 23, 2010, 11:34:00 AM
Hello Doc, thank you very much for this update !

i just shot a 400 pounds red stag here in Alps mountains with my 46 pounds recurve and a 100 %  "doc arrow" ... complete penetration from a tree stand  died in 60 meters ...

i think your woks in arrows optimisation change a lot in the world of bowhunting

Thanks again ED and best wishes for 2011 !
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Steve H. on December 23, 2010, 06:34:00 PM
Merry Christmas to us!
Title: Re: How much penetration gain per 1% FOC increase?
Post by: aussiebowhunter on December 26, 2010, 05:53:00 PM
Dr asbhy thanks again, i ve always followed your reports and enjoyed taking in all the info..have a top xmas and thanks for all your work..

goodhunting
pat
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Ragnarok Forge on December 28, 2010, 04:49:00 PM
I will be reading this with interest.  I am shooting 584 grain arrows with 29% FOC.  I am working up some 700 grain arrows around 28% foc for a trip to OZ.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: oxnam on December 31, 2010, 10:32:00 PM
Dr. Ashby - I just read the report and I was curious, what was the exact arrow setup for the 650 grain arrow that did so well?
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Dr. Ed Ashby on December 31, 2010, 11:34:00 PM
The 2008 Updates, Parts 4, 5 and 6 all deal with the Ultra-EFOC setup. The construction specifics for that 655 gr. Ultra-EFOC arrow are in the 2008, Part 4 Update. Here's the link.

 http://www.tradgang.com/ashby/2008update4.pdf


Ed
Title: Re: How much penetration gain per 1% FOC increase?
Post by: oxnam on January 01, 2011, 11:02:00 PM
Just what I was looking for, thanks.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: term on February 07, 2011, 03:47:00 PM
Thank you for all of you hard work on this issue. I dont go after any (BIG) game, but I do want my 160gr snuffers to help me out when I make a poor shot on 200lb plus whitetails. I have heard folks say that FOC was not an issue on deer. But on a bad shot it may be the main issue. TERM
Title: Re: How much penetration gain per 1% FOC increase?
Post by: DesertDude on April 13, 2011, 12:06:00 AM
As always,  Thanks Doc.......
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Bobaru on May 09, 2011, 12:45:00 PM
Sorry, I can't reproduce your work Ashby.  

Give us your data points, so we can determine variation within each type of arrow.  In that way one can determine if there is a difference in penetration with an increase of FOC.

All the results I get show there is a 0% increase in penetration with a 1% increase in FOC.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: monk on May 09, 2011, 05:35:00 PM
What is FOC?
Title: Re: How much penetration gain per 1% FOC increase?
Post by: JohnnyWayne on May 09, 2011, 08:22:00 PM
Balance point of the arrow, "forward of center"
Title: Re: How much penetration gain per 1% FOC increase?
Post by: monk on May 11, 2011, 10:28:00 PM
So your all saying tuning is unnecessary just shoot the heaviest Broadhead you can find?
Title: Re: How much penetration gain per 1% FOC increase?
Post by: wtpops on May 12, 2011, 12:03:00 PM
Quote
Originally posted by monk:
So your all saying tuning is unnecessary just shoot the heaviest Broadhead you can find?
If this is a serous question, the answer is of course not. In short (very short) Dr. Ed is giving us (you) the info to make the best penetrating arrow out of a well tuned setup.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: AKCrazyhorse on May 12, 2011, 12:14:00 PM
In every report ever published by Ashby he has unequivocally stated that perfect arrow flight is the NUMBER ONE factor in arrow penetration.  Not UEFOC, not threshold weights, not broadhead design, not arrow shaft diameter. Holy mother of God folks read what the man is saying before making uninformed, uneducated, replies.  His "recommendations" are how to increase your penetration on marginal hits, through HEAVY bone, assuming you have a well tuned set up.  For guys hunting turkeys, white-tails, javelina etc. it probably doesn't amount to a hill of beans.  For guys hunting, Moose, Elk, Big bear, Bison, African and Australian buff, etc.  It may have more importance.  I for one have bought into his findings, maybe it makes me right and smart, maybe it makes me wrong and not so smart.  What it does make me (with 100 percent certainty) is more confident in the ability of my equipment to do the job I'm asking of it, and THAT may be the most beneficial result of all this.  Thanks Doc.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Mint on May 12, 2011, 01:53:00 PM
I noticed a big difference in penetration when I switched to a heavier spined carbon with 50gr brass inserts and 200gr phantom broadheads.     ( 23% FOC ) Every 100lb hog I shot was a complete passthrough and I don't think I would have gotten this big boar without the change in setup. He was a fighter and the shield was close to two inches thick. The arrow was stuck in the off side shield.

  (http://i369.photobucket.com/albums/oo137/jm9862/Hogs/230lbgreyboar.jpg)
Title: Re: How much penetration gain per 1% FOC increase?
Post by: monk on May 13, 2011, 04:59:00 PM
Thanks for the clarifications.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Doug Treat on May 20, 2011, 08:10:00 PM
I'm very interested in this latest report.  I now have to shoot a 41# bow due to shoulder problems and I hunt elk with it.  Last year I was confident (Thanks to the good Dr.) in my arrow setup shooting a 630 gr. arrow (just a bit under the 650 threshold recommended) with 20% FOC.  I shot a cow elk and got 20" of penetration after hitting a rib.  My bow was only shooting those arrows at 140 fps. Nobody I know would recommend shooting an elk with a 41# recurve (and people don't believe me when I tell them that I do), but now I would recommend it if the perfect arrow is used.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Mint on May 24, 2011, 03:21:00 PM
Doug, my friend had the same experience but with a 6 x 5 bull and he pentrated up to the feathers with a 45lb recurve. The bull only went 60 yards.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Ragnarok Forge on June 07, 2011, 10:38:00 PM
My wife and daughter will be hunting elk with 40 lb bows and efoc arrows this year.  I am not the least
Bit worried about their arrow penetration.  All thanks to Dr Ashby's studies.
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Troy Breeding on July 21, 2011, 08:08:00 PM
Anyone would think I could remember all these things since I worked (somewhat) with Ed when he was doing part of his studies. Like anything else when you drop off the map for a few years you start to develope the CRS syndrome.

I posted some of these same questions on another thread over at the powow talking about the Tuffhead broadhead.

Thanks for the help amigos...

Troy
Title: Re: How much penetration gain per 1% FOC increase?
Post by: Yeoman Bowman on July 29, 2011, 08:26:00 PM
Great post Ed. Thanks for the info.