Home Forums Hunting & Shooting Bowhunting Broadhead tip comparison evaluation

After some discussion online (on another site) that centered around broadhead tip designs and what is a COC (Cut On Contact) broadhead VS a chisel tip VS a cone tip VS other styles of broadhead tips and their effects on penetration. It was suggested that a comparison should be done. I volunteered to do that comparison because:

1. my Son and I have a bit of a broadhead collection (about 300 heads)

2. I hunt with my own homemade broadheads so I can be impartial.

3. I'm into this sort of thing.

4. Everybody else had a life.

**** DISCLAIMER ****

To call this a scientific test would be unfair to every scientific test ever conducted. This is simply a COMPARISON of penetrating ability through a given material to see the force needed for different broadheads to cut, poke, ect through the medium. I know this is not a deer hide but what the material is, is not important so long as all the heads are compared using the same material.

Every head was given 5 chances to penetrate the material and an average was taken. I set up my digital camera in front of the scale to record both images and video and then later captured a still of the video that represented the peak force immediately prior to going through the material.

The set up I used is as follows. I made a wooden frame by cutting a hole in a piece of particle board. Over that hole, I will lay the material to be punctured. To prevent the material from simply being pushed through the hole I used wood blocks to clamp the material on two sides. The reason I did not clamp the material on all four sides is that I would have lost the stretch factor and the material would have been tight (Like a drum head) and would have required almost no effort to make a hole through it.

The wooden frame sat atop wood blocks to provide enough depth clearance to prevent the longest of the broadheads from bottoming out. All of this wood applied a force on the scale so I adjusted the scale back to zero. The scale and the wooden frame were then set under the head of my drill press. In the chuck of the drill press I chucked an arrow insert so I could quickly change from head to head without damaging the threads on the broadheads.

With a head loaded in the drill press, I would use the drill press handle to lower the broadhead onto the material and continue to apply a constant and even force until the head went through. In front of the drill press sat my camera on a tripod to capture the data so I could focus on applying the force without worrying about having to read the scale.

Here is a picture of the set up.



Here is the test material. It is a cloth that has a rubber/vinyl coating on both sides and is used for seat covers.



I cut strips of the material to make it easier to manage moving it over the hole in the frame each time I did a test.



To set up a sort of control or perhaps a worst case test, I used a practice point (field tip) and then a Hilbre broadhead to show examples of what I plan to do with a series of broadheads.

First, the practice point. Here you can see the "Stretch factor I was talking about earlier and why I did not clamp down all four sides of the material.





I turned on the camera and did 5 tests with the practice point. The results were very consistent. It took 20 pounds of pressure to poke through the material. Here is a still captured at the peak force moment.



And here is a video of what it looked like in real time.

[img]http://i175.photobucket.com/albums/w124/bow_project/BH%20test/th_MVI_0666.jpg[/img]

That was clearly a puncture with no cutting taking place and I did it to explain what I am planning on doing with all the heads and because a few of the heads I plan to test, have a secondary point that will have to employ a bit of "Stretch Factor" prior to the blades cutting the material.

The next sample was done with the Hilbre. This head had to be sharpened because it is pretty old and dull. All the others will be tested "As Is" meaning right from the package but I completely understand that hunters will sharpen or make improvements or modification to heads to make them perform better (Such as sharpening the Trocar tip of a Muzzy)

Disgital still of the Hilbre. It took 0.7 Lbs of force to pass thru the material with the Hilbre's needle tip. (I am able to zoom in on the scale)

[img]http://i175.photobucket.com/albums/w124/bow_project/BH%20test/hilbre.jpg[/img]

Hilbre Video.

[img]http://i175.photobucket.com/albums/w124/bow_project/BH%20test/th_MVI_0746.jpg[/img]

Now you understand the process I plan to use with all the heads that I will compare. When it comes to cone tip, chisel and Trocar tips, The force that I will consider the peak force is the highest value reached prior to the point the blades start cutting. That is because that IS the tip style of those types of heads that I am comparing.
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NOW! Before we go any further, lets get real. We all know that your broadhead moves a lot faster than the speed in which I am using to penetrate this material and we all know that the broadheads I am about to compare will go through an animal at lightning speed from your bow and bury itself into the dirt on the other side. The same can even be said about the practice point in the first test so don't think that I will be providing proof that one head will out perform another in actual hunting conditions. This is only a comparison from head to head of the tip's ability to go through material.

At the same time, for those that use low weight and slower bows and who are looking to squeeze out every ounce penetrating ability from their gear, this may be of value. The same can be said of the Traditional bowhunters (I'm one of them) I use a 45# longbow that shoots my 500+ grain arrow a blazing 142 feet per second. But again, this only a comparison of tip designs and not the entire head. That would be another comparison to do.

This is also a sort of "Hide" penetration comparison and not a bone busting TEST. That too would be another comparison all together. Heads with a fine, needle point that will do well in this test, may not do so well in a hard impact or bone test as those tips may break or curl.

Now that we are clear on what this comparison IS as well as what it IS NOT, we can proceed.