Single Bevel Broadheads and Rotation

[PCF]

I have been researching the thickness of different broadheads and it raised a question to me.  Is there any correlation between the thinkness of a single bevel head and amount of rotation upon impact? Giving they are the same degree bevel.

[SlowBowinMO]

Yes, you'll get more rotation out of a thicker blade.  That's why the best single bevels are usually at least .050" thick.

[Kevin Dill]

Thicker blade = more bevel surface = greater rotational force and degree.

[Charlie Lamb]

Stands to reason that the thicker blade would rotate more. I might add that I'm a skeptic as to whether the value of rotation is significant.

[Zradix]

yep, the thin blades just don't have as much slanted edge pushing the head around.

maybe you've been a trad hunter for years and have forgotten more about it than I'll ever know, maybe you haven't..but just in case...here are a couple thoughts I'll give up in true sincerity.

I wouldn't let the amount of rotation influence your broadhead choice much unless you're going after BIG RIB BONED game. Even then I'd be thinking thicker=stronger...the added rotation for bone breaking is just a bonus.

I have a very inquisitive mind and I like to research all the details of things for fun.

I've done it for a few years in this trad way of hunting.

if your curiosity gets the best of ya research away buddy.

But speaking from experience, after thinking...a whole lot of research, actual sleepless nights with my mind whirring trying to figure the absolute best of everything....

It get's so much more fun and relaxing once you realize you just need a straight shooting arrow with a sharp broad head...darn near any broadhead.

...and some practice..lol

Good luck in the woods!
   

[Bjorn]

I don't know if fletching is sufficient to cause rotation in a 2 bevel-never really noticed any.
Pulling a single bevel out of a target the rotation is obvious so a single bevel should fly better.
If it hits bone a single bevel might act like an axe blade splitting wood.
You can get a better cutting edge on a single bevel; although these days most 2 blades are really well done.

[awbowman]

Originally posted by Charlie Lamb:
Stands to reason that the thicker blade would rotate more. I might add that I'm a skeptic as to whether the value of rotation is significant.

Spoken like a man that has piled them up for a long time without the new stuff!  

[Steve O]

Originally posted by Charlie Lamb:
Stands to reason that the thicker blade would rotate more. I might add that I'm a skeptic as to whether the value of rotation is significant.

Charlie, I asked Blake Fischer, owner of Eclipse broadheads the thickness question.  There is an optimum thickness and that is what the Werewolves are.  I want to say .050".  I bet if a guy was to measure any Abowyer, Eclipse single bevel or ABS broadhead, they would be that thickness, whatever it is if my memory does not have the right figure.  More othickness or r less, you do not get as much bang for your buck.

On the rotation issue, I have been in the same camp until I attended a seminar by Dr. Ashby at Kalamazoo this past January.  He demonstrated something he called (I think this is what he called it) the "spiderweb" effect.  He took a hankerchief and wrapped it around the head, then pulled it thru, simulating animal internal tissue.  He opened up the hanky and it looked like cheesecloth...it was amazing!  I think Bill Dunn or Todd Smith have it somewhere here or on their site archived.  I will dig a round after the trick or treaters are done and see if I can find it.

[AWPForester]

X2 with eveything Bjorn said.  Ecspecialy ewith the axe effect ob bone.  But, I got a question.  If the broadhead is shot into a fleshy non consitent medium like animals, what makes it keep twisting if the "target medium" isn't hard enough for the broadhead to track.  The theory of the single bevel is that the medium is what causes the broadhead to continue to track in reference to the bevels right?  If it if going through soft organs, how are those organs "tracking" the head when they are soft and being cut out of the way.  Demonstrations for thiis can't be mimicked by hankerchiefs or anything else.  When I open up my animals they are bloddy, clotty messes that look like cheese clothes.  Just wandering.  God Bless

[Kevin Dill]

The greatest tendency to rotate will be through the firmer mediums, as they provide enough resistance to the bevel for it to 'push off' and rotate. The unknown is what type of counterrotational forces might be present at a given moment...working to impede rotation. Greatest rotation (at a given moment) will be when the medium is firm toward the bevel and softer away from it. In a consistent medium, rotation will be consistent, but it will also decrease as the medium gets extremely soft (say inside the gut) or hard (inside a bone). There will be a point of optimal rotation, though impossible to find it in a multi-density living animal with all the inherent variables.

Trust me....Holiday Inn Express guy.    

[Zradix]

Yep, the more solid the medium the more "twisting power" you get.
..but the twist will still be there in softer mediums like lungs.

if you blew air by it fast enough even it would cause the arrow to spin.

if you happen to have a single bevel cooking/chef's knife, try cutting a straight "chop" through a few different things..cheese, butter (cold and soft), tomatoes, you'll then be able to see and feel what happens.

[Zradix]

truly though, I believe this stuff doesn't make or break a good kill shot unless you're hitting BIG thick cape buff like ribs and you need em to CRACK and let your arrow through.

[Steve O]

I pretty much poo-poo'd all the single bevel advantages untill I saw what an Abowyer Brown Bear did to a solid black bear shoulder/knuckle.  If I am going to shoot a 2 blade, it will have a single bevel and it will be an Abowyer.

[Montanawidower]

X2 what Steve O said.  

 I have seen some good, bad, and ugly results on elk over the years with various heads.    Single bevels have made my last 4 elk clean, deeply penetrated kills.  

With that said, I doubt on whitetails it makes much of difference except in the knuckle area.

[Steve O]

OK, I just did some looking.  It is the bevel ANGLE that is optimum at 25 degrees.  All three companies heads I mentioned are at 25 degrees.  The ABS and Abowter heads are .072" thick and the Eclipse single bevel Werewolves are .057" thick.

Will look for that other info still.

[Steve O]

OK, I forgot one of the really GOOD guys in traditional archery...Joe Furlong of Tuffhead Broadheads.  His site is like an encyclopedia of single bevel info.  His heads are .060" thick with a 25 degree bevel.  He has all kinds of links and info on the site.

I did find a youtube video of part of Dr. ashby's Kzoo presentation.  It is the "Starburst Effect" that I was trying to remember.

 http://www.youtube.com/watch?v=u6BLX3zlJkk&feature=youtube_gdata_player

[Brad Arnett]

Thanks for the link Steve, it was an interesting video.

[Steve O]

No problem.

Here is a link to Joe's "education" page:

   Single Bevel Info page

[Mike Vines]

I sat front and center at Ashby's seminar, and man was it A LOT of info to digest in the time he had to explain his research and findings.  I'm glad they recorded and made available to us this awesome amount of info.  I know it sure changed my way of thinking.  Thanks for the video links Steve.

[maineac]

I figure Ashby's data has enough strength to make using a single bevel my choice if I shoot a two blade.  If I hit a shoulder blade, or knuckle the added advantage might make the difference in a recovered animal.