I'll be darned! They do rotate.

[30coupe]

I got some Zwickey Deltas the other day and decided to single bevel a couple of them. At first, I was afraid I'd lose a lot of grains, but as it turns out, the 135 grain Deltas come about 10 grains heavy, I suppose to allow for sharpening.

Anyway, I flattened the edge down to the start of the bevel and filed in a new single bevel (left bevel). The triple layer stuff at the front still has a bit of a double bevel, but what the heck. I took one out and shot it into my 3d deer, just to see how they would fly...darts! Then as I was pulling it back out, it felt like it was rotating...hmmm. I shot one into a thinner part of the target that hadn't been hit before. The head had rotated about 1/4 turn on its way through maybe 5" of foam deer. It seems to me, after shooting a few more times, the arrow rotates about 1/4 to 1/2 turn depending on the density of the foam and the thickness.

Not that I doubted Dr. Ashby, but it's pretty cool to see it first hand. I know this was foam, but I don't see any reason to doubt that they will do the same thing on real critters. Unfortunately you are going to have to wait until October or so for an update    :rolleyes:

[IronCreekArcher]

I LOVE it...another convert (maybe?)!!!!  I am looking forward to your updates this fall.

[SlowBowinMO]

I've worked over a number of Magnus I 2 blades, and yes I've found the same thing, they do indeed rotate.  

[bm22]

Now think how much more rotation you would get with a thicker head like a grizzly!!!!

[ranger 3]

This is a good example of how they rotate. Look real close and you can see where it stared and where it ended up. This was done by pushing on   the nock.
   http://i297.photobucket.com/albums/mm216/ranger500us/IMG_0621.jpg

[Morning Star]

How about the wider single bevels like the abowyer heads.  Do they get more rotation than say a grizzly?

[IronCreekArcher]

Yes they do because the surface area of the bevel is greater thus increasing the rotation factor...or so I was told by Dan at Abowyer a couple of weeks ago.

[Sharpster]

Actually there are a few characteristics that influence how much a single will rotate.

A 3:1 profile will rotate more than a shorter, wider design will, and as stated above, a thicker blade with a continuous wide bevel from tip to heel will rotate more than a head that is only thick up front. The other is sharpness. The head has to cut in order to rotate so the sharper it is, the less resistance to rotation from the cutting action.

Ron

[Bjorn]

Just like rotating the axe on impact with the log helps make an easier split. So too with the rotating BH.

[todd smith]

I'm a believer in the thick stock, wide-beveled single bevels, but I have yet any critters to share the results of...  Come on October...    

[30coupe]

Originally posted by bm22:
Now think how much more rotation you would get with a thicker head like a grizzly!!!!

Grizzlies rotate the wrong way for me. I shoot left wing feathers. Since folks have been killing stuff quite well with Deltas since the 1930's without rotation. I think the added rotation I get with these will do me just fine. Even if they don't rotate as much, the cut is 1-3/8" wide...I like that idea.

[30coupe]

I just can't make myself spend that much for broadheads to kill whitetails and turkeys. They can only get so dead. If I were going after something that might try to kill me back, I'd consider the high priced spread.    :rolleyes:

[Guru]

You guys should make a new X-files movie          

BTW...since when isn't a sharp broadhead "reliable"?

[Jason R. Wesbrock]

Originally posted by Dave2old:
I do care about the freedom the enjoy unrestricted and open discussion of the many and varied possibilies in life ... and in this case, in fast, humane death of the animals we hunt when the much-hallooed but tremendously unreliable "sharp broadheads and perfect arrow placement" fail us. Dave

I understand what you're saying. But respectfully, if my ability to put an arrow where it belongs was "tremendously unreliable," I'd personally restrict my shooting to foam animals instead of real ones.

[pseman]

Do you get similar rotation when shooting through soft, mostly liquid substances like a deer's vitals? Once past the skin and very thin muscle layer, does the rotation continue?. I honestly don't know, but vitals like the lungs, blood vessels, and other organs(except the heart) are largely soft tissue made up of largely of blood. I just doubt that at that point rotation will occur and if it occurs will it increase killing effect.

[Don Stokes]

I learned long before the single bevel mystique was created that the spiral in my fletching made the broadhead (old-fashioned double bevel) rotate in the target because the arrow is spinning when it hits, regardless of the brand of broadhead. Shooting foot-thick styrofoam, when the broadhead exited the other side, I learned to rotate the shaft about a quarter turn to get the blades realigned with the hole for extracting the arrow from the target. If I pulled straight back the blades hung up because of the rotation.

Maybe the single-bevel rotates more, but I've never lost an animal due to lack of rotation. From the pure physics point of view, additional rotation increases friction through the application of lateral forces to the medium, which would theoretically act to reduce penetration. Unless you're shooting elephants, it probably doesn't matter. Not trying to start an argument, just sharing my experience from 45 years of bowhunting.

[James Wrenn]

I personally can not see how the rotation could not be robbing energy from the arrow myself.Of course I guess it is a mute point for what most of us hunt anyway.Any extra penitration would have to be measued in dirt on the backside of whitetails.    

The day I have to worry about penitration on a deer will be the day I quit hunting them.I will stick to foam animals where shooting them in the wrong places does not hurt anything . jmho  :D

[kevgsp]

They may not be your head of choice, but they do rotate.

Take a close look at the edge profile, then at a double bevel... all the presure is on one side forcing the blade to turn as it cuts.  Go cut something.

[Guru]

I don't think anyone is saying they don't rotate...anyone that's cut something at home with a single bevel kitchen knife knows it is not easy to cut straight with it....

[Adam Keiper]

Not to take away anything from single bevels (I shoot Grizzlies), but every standard broadhead that I've shot also rotates 1/4 to 1/3 turn into foam just from the arrow's incoming rotation.