The main reason people go to single bevel heads its their ability to spit bone where all other blade profits and configurations get wedged into bone and stop all forward movement.
I started exploring and making my own single bevel Broadheads 13 years ago. I was mostly hunting with all homemade trade gear and slow and low poundage longbows needed all the advantages I could find. I was doing a lot of custom butchering at that time so I had cadre deer to test my heads on. (With permission of the person dropping off the deer)
Here is one such deer and my homemade bow and homemade single bevel heads back in the day.
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. (wink)
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.
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.
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.
I then removed the shoulder and boned it out.
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.
As expected, the single bevel head is a real bone breaker/splitter. I know this is a very 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
The year I was doing this testing was 2008. I was contacted by Traditional bowhunting magazine. They asked me to write a companion piece with DR. Ashby regarding single bevel head.s I think that was published in Aug of that year.
If you visit the bone broadhead website (sellers of single bevel broadheads) you will see that same split scapula I posted here. I learned they stole that image from my blog. When they did that, they had yet to produce their first head but they tried to pass of my image as an example of the damage their heads do. I contacted them and told them to either take down my image or properly credit the photo. They keep the image and did as I asked.
To each their own but the broad head is not where you should be looking to save a few $ imho
