Primitive Archer
Main Discussion Area => Shooting and Hunting => Topic started by: WhistlingBadger on January 06, 2020, 08:53:56 pm
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I've always used double bevel (Zwickey eskimos, to be exact). Wondering what the pros and cons are for big game.
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They both work well for taking game.I think the thing about single bevel if in combination with fletch helical that allows the arrow to spin the same as the bevel the momentum, both forward and in spinning will split bone if it's hit plus it supposedly aids penetration.
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I think it is just marketing to get us old guys to buy new heads. I sure have not put enough broad heads through deer to form an opinion. Clay Hayes uses a single bevel.
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I think the difference would be hair splitting,, with a primitive bow,, but I am just guessing,,maybe there are advantages I have not come to appreciate,,,
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My test results. Using two separate 3/4 " pine boards and shots out of a 43 pound bow, same arrow weights, an Ace 160 grain double bevel went in 5/16 inch, cracked wood 4 inches. The Grizzly SB 153 grain went in 15/16 ", and made a 6 inch crack. Didn't shoot on a moving mulie buck at 20 yards (that is separate topic), so as if yet, only targets, and an S shape cut occurs, whether cardboard or wood. Profile is also what I like, so maybe an advantage there w 3to1.
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I would think the single bevel is more appropriate to a thinner (saw blade) trade point. I am assuming the bevel is cut on opposing edges, i.e. cut one bevel, then flip the point and cut the other.
Hawkdancer
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I've made and used both the single and double beveled blades for over twenty years. I've taken a number of deer with both, but the only arrows I've lost from pass-throughs on deer were single beveled broadheads, never a double bevel. Shooting lighter weight hunting bows with a short draw length is about the greatest advantage I can think of. For me, the single beveled blade is easier to make, and provides a super sharp edge.
Look up Dr Ed Ashby's single beveled broadhead study for a better understanding of how and why they provide an advantage for today's hunters......Art
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I've killed a fair amount of deer with 3 blade, double bevel and single bevel broadheads. The only heads I've used for my last 30 or so deer have been single bevel. Once I read Ashby's Arrow Lethality Study it opened my eyes to the advantage of single bevel heads. The number one thing I noticed that is rarely mentioned is that the recovery distance has been significantly shortened. Almost every deer I've killed with a single bevel Tuffhead or Grizzly El Grande has expired within sight... Most travel less than 30 yards. 90% of shots are pass thrus with 40 - 50 # bows and 600+ grain arrows. I believe the most important part of my hunting gear is the broadhead so I use what has given me the best results. Anyone interested in this subject should read Ashby's reports.
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Is the distance travelled directly related to the fact that they are pass through shots or does the single bevel somehow do more damage?
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DC, like someone above said the single bevel head makes an "S" shaped hole instead of a simple slit which makes a larger, more open wound allowing more blood flow, more dramatic hemorrhaging.
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Does it not matter then if the blood can get out of the body? Like a pass though leaves two holes where the other leaves one hole with an arrow stuck in it.
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The reason I use single bevel is ease of sharpening, as well as easier to get a consistent shallow edge. I really dislike sharpening double bevels.
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Does it not matter then if the blood can get out of the body? Like a pass though leaves two holes where the other leaves one hole with an arrow stuck in it.
Even if the blood doesn't leave the body, blood will start filling up in the body where it shouldn't be so its still loosing blood, killing it. The blood (if you hit the lungs) will start pouring into the lungs suffocating it and also collapsing the lungs, killing it. If you hit the chest but miss the lungs and heart, blood will start filling up in the chest cavity, killing it. so even if there is little (to none at certain times) blood coming out of the body it will die but that gives you a bad blood trail.
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One thing to be aware of with the single beveled blade is to use a tanto double beveled tip. I had noticed on several of my deer the entrance and exit wound didn't line up with the angle at which they were shot. Broadheads seem to be planing inside the deer. I mentioned this in another thread, but it's worth mentioning again. Dr. Ashby suggested I double bevel my tips on my broadheads to prevent what he called "deviation of penetration. This solved my problem, and know doubt, enhanced the arrow's forward momentum.
Something else I noticed on lung shots, instead a simple slit through them, they were mangled up. Dr. Ashby mentioned this also. You also get, what seems like, a larger exit wound.…..Art
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Thanks for the input, guys. I'll read the Ashby study this weekend. If they're easier to get sharp, that's enough for me.
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They both work well for taking game.I think the thing about single bevel if in combination with fletch helical that allows the arrow to spin the same as the bevel the momentum, both forward and in spinning will split bone if it's hit plus it supposedly aids penetration.
which way does the single bevel rotate? How do I match that to my fletching? I usually have left-wing fletches. I think they rotate counter-clockwise (Anti-clockwise if Del is watching :-) ). which bevel would also rotate in the same direction and why?
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I think you want the bevel on the left for left hand fletching.
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Artcher1, I followed you advice. I've often wondered about those tip. Double beveling 8 tips took an hour. They feel much better. Thx for tip.
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I was recently was gifted some large chunks of foam (16inch foam pipe line pigs), I thought that they would be like a poor mans 3d target. When shot with zwickey double bevel heads they made a slit on entrance and exit, but grizzlie single bevel heads cut out a tornado funnel shaped piece of foam, indicating a much greater wound channel. I have always liked the single bevel, and they are easy to make and sharpen. If you use the wrong wing fletch they will make only a slit on exit. If you really think about it the single bevel is the only way to go.
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For what it’s worth I am a Professional Hunter in Tanzania and I have guided several bow hunts for Cape Buffalo. The single bevel heads do everything that Ashby says - but their main advantage is when they hit heavy bone. You could shoot a double bevel and a single bevel at an animal and if neither hit heavy bone you would not notice much difference in penetration but as soon as you introduce heavy bone, the single bevel is streaks ahead. What it does is twist as it passes through the bone and this causes the bone to split. This means the bone is not creating friction on the shaft passing behind. I had a long and heated difference of opinion with a client who brought a German kinetics double bevel saying he had tested it against a single bevel on a piece of plywood in front of a foam target and it penetrated better than the single bevel. I pointed out to him that a much fairer test would be a piece of lumber - which would split the same way bone does. There are no downsides to single bevel heads and lots of upsides. What Ashby says is spot on. I have tested various arrows on dead buffalo and he is completely on the money. If you shoot a single bevel into a block foam target you will notice as you pull it out that the arrow has twisted as it penetrates.
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Again, thanks for the input, guys. I'm going to have to get some single bevels, in addition to upping my arrow weight.
One thing I wonder about. I fletch my arrows with wild turkey feathers, and I use both left and right wing. I've never seen a bit of difference in how they fly, but I have to admit I'm not crazy about having to buy (and keep track of) left and right beveled heads. I could just fletch all my hunting arrows left and save the right wings for targets and bunnies. But what I really like to do is make all my arrows the same, and put broadheads on the best-flying ones right before hunting season.
That's about the only advantage I'm seeing for double bevel. That, and I already have some. ha ha
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I don't have enough bow hunting experience to state a point of view, but I have heard from other hunter that Cape Buffalo are rather tough to stop! Got to finish the batch of saw blade
trade points waiting in the work space - single bevel for right wing this time.
Hawkdancer
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You have to match the bevel to the fletch so that the spin on the arrow in flight and the induced twist that the arrow creates as it goes through bone are in the same direction. Otherwise you are wasting energy spinning and arrow one way in flight and then it goes the other way once it hits bone. Having said that, I suspect so long as your arrows are tuned and the bevel of each arrow head matches the fletch, I doubt you fill notice much difference at hunting ranges whether you shoot all left bevel, all right bevel or a mixture of both. But given bevelled broad heads are more expensive than feathers I would just pick one or the other and stick to it. I have used the Grizzlies and they are tough as nails and pretty reasonably priced. The Tuffhead website has all of Ashby’s articles in one place. He actually shoots a straight fletch for himself I believe. He is very big on weight forward of center arrows. This in itself puts less onus on the fletching to stabilise the arrows. If you are in any doubt about the effectiveness of single bevels this is a pretty good video. https://m.youtube.com/watch?v=BGxWyCQ1lWM.
Remember - there are other more important things for arrow penetration than single vs double bevel - weight, shaft and head toughness and integrity and forward of center arrows of 19% or higher - but there is no downside as I see it to a single bevel - and I have seen it with my own eyes - so I am a full believer.
https://www.ashbybowhunting.org/
In case you are wondering ... I am in no way affiliated with any of this ... I just think that it is an incredible resource for responsible bow hunters to make use of
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I don't know about better penetration but am convinced that the single bevels cut better if spinning the proper direction.
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I was wondering whether any of the English “warbow” guys have ever measure old English arrows for High FOC; I enjoyed Ashby’s article on the heavier tipped arrows being preferred in Papua New Guinea. I can’t help but think that trial and error would have led an armour piercing arrow design to the same conclusion?