Single and Double Bevel cut profiles through varying materials

Sharp Things

Lil-Rokslider
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My new 250 grain Single Bevel Cutthroat broadheads arrived for my Water Buffalo hunt so I bought a few Rutabagas and made a video comparing single and double bevel broadheads and their cut profiles through a variety of mediums.

Since we do not have a ready supply of actual bone in mid March, the Rutabaga was a "Bone substitute" since it reacts a lot like bone from a fracture standpoint and its cheap. Its not ideal but its a pretty consistent medium for this sort of experimentation.

There has been some dispute as to the cut profile of single bevel heads. some claim to see an "L" shape, others see a smile "(" but we always see an "S" regardless if the head is pushed by a compound or longbow and regardless of arrow weight.

The leather and foam and rutabaga all had the "S" shape cut.

[video=youtube;gYKUGjVBV7k]https://www.youtube.com/watch?v=gYKUGjVBV7k[/video]
 

Beendare

WKR
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I talked to a well known BH manufacturer that doesn't do the SB thing....he said it doesn't matter.

Bill From Iron Will stated the same on the Broadhead forum of AT....doesn't think SB is a factor.

I dunno.....I've split bone with the VPA 2 blade wedge shaped head....and Bowsite did a test years ago on Cape Buff where he split bone with a double bevel....so those work too.

Ashby claims an advantage to SB.

Maybe there is a slight advantage to single bevel...I dunno......but I've never seen a good apples to apples test where they take the same exact BH in both bevel configurations testing side by side. Everyone takes their favorite....and sets out to prove their theory correct.

One thing is fact; the SB is a less supported edge so a guy wants to be sure the SB head they have uses high quality steel so the edge stays sharp.

Have you ever asked yourself why most knives have a double bevel? Its a stronger more well supported edge.
 
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As long as they are sharp, fly well, are decently designed and constructed all broadheads work very well! I noticed exactly no advantage with the single bevel design in limited use 3-4 years ago (one grizzly, a couple whitetails, a black bear and a Roosevelt elk). Double bevel designs sharpen easily and are sharper in my testing than a single bevel and are my preference.
 
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Sharp Things

Sharp Things

Lil-Rokslider
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When I was designing my first single bevel broadhead over a decade ago, I was skeptical but over a decade of use and testing I have become a fan. I dont use them for everything as I like to shoot every broadhead I can get my hands on. Ive killed over 100 deer with a huge variety of broadheads (both fixed and mech heads) and pigs with Woodsman and Huge Rothhaar Snuffers and recently a Vancouver bull with that giant Snuffer but as I prep for water buffalo, Im inclined to go back to thick, single bevel and really great stteel (Rockwell hardness 55). That steel, thick blade material and 22 degree bevel is a very strong edge. I will know more after putting one through the leaf springs the water buffalo carry on their sides.

In my early testing, I was making my single bevel heads with relatively thin steel and a low weight homemade longbow pushing an arrow about 150 FPS and yet the bone splitting results speak for themselves and are very telling.

I made three shots from 10 yards with my 45 pound longbow that shoots an arrow at a blazing 142 FPS. the first two were through the ribs and the final one hit the shoulder blade at the point where the flat and the "T" meet, right near the ball joint. This is (in my opinion) the largest and thickest bone section in the upper shoulder. I admit that hitting this far forward is not a good place to aim on a live animal but things happen beyond our control. I of course hit this spot with pin point precision on purpose.

deeranatomy.jpg


The rib shots were complete pass throughs but the shoulder shot ended up with just the fletches sticking out entrance side. I know there were no lungs in the deer but they don't offer much in the way of resistance any way. Also consider that this deer was cold and stiff as rigor mortise had set in so I consider all things equal.
head_test2.jpg


Right off the bat, I noticed the "S" shaped cuts that Dr. Ashby had spoke about. This was the case on both the entrance and exit holes.

head_test4.jpg


*** Word of caution***
When you pull the arrow back out of the deer (through a bone) and you have sharpened your broadheads on the trailing edge as well as the main edge. Make sure to keep your fingers clear even though you need to hold the deer steady while retrieving the arrow.

head_test3.jpg


After a brief bit of first aid, I began to skin the deer, I noticed that both of the rib shots had completely missed hitting ribs on both sides. My goal was to break a rib to see the results but I must have used up all my luck..... I mean skill on that shoulder shot.

head_test5.jpg


I then removed the shoulder and boned it out.

head_test6.jpg


Just as described by Dr. Ashby, the "S" shaped cut and the bone had split completely being held at the joint end by only some soft fibers.

head_test7.jpg


head_test8.jpg


As expected, the single bevel head is a real bone breaker/splitter. This was a small deer but again, I was using a rather low power bow. Take from this what you will but I am even more pleased with the single bevel heads. This sort of thing is not necessary with todays super fast and powerful bows hunting whitetails but for those using traditional archery gear, or those going after large or dangerous game, we are looking for every advantage we can get. Since I love to explore and try every head I can get my hands on and because I test extensively, I can say first hand that I firmly believe that there is an advantage in using single bevel heads so long as they are made of very high quality metal.

People need to do whatever level of research and testing for themselves to arrive at their own conclusions. Then they will have made the best and most informed choice they can make. Since I can get a single bevel head razor sharp, there is no settling for a lesser sharpness by going with single bevel. I count the edge of both types to be equal.
 
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