FOC is very important as well as with my single bevel broadhead will go right through both shoulders no problem I've done it, do you know the benefits of a single bevel vs a traditional fixed blade Justin ? If not I can give a brief rundown a single bevel is rotating in the cavity with the high about of KE and momentum along with FOC the arrow is forced through the bone while still spinning from only having one bevel and with cause the bone to crack and the arrow will continue on. Just a brief overview Sent from my iPhone using Bowhunting.com Forums
We can argue all day about this but check out the highmomentum Facebook page if you want facts from a ton of different sources with tons of years of experience .... Sent from my iPhone using Bowhunting.com Forums
Check out dr.ashbys studies on high weight and FOC arrows he has a hand full of them that everyone can benefit from in an arrow aspect with their archery set up. Sent from my iPhone using Bowhunting.com Forums
I understand all of that - but again we're talking solely about FOC in this conversation - not single bevel broadheads. Assuming you have two nearly identical arrows both weighing 500 grains, both using the same broadhead and both shot from the same bow - yes, you'll likely see a difference in penetration from the arrow with higher FOC. Fair enough. But when you start talking about a situation of two different arrows, two different broadheads, two different bows it's almost pointless to talk about FOC as there are so many other factors that play into how much penetration you'll get. FOC alone isn't going to dictate one being better than the other. And I believe the arrow will certainly influence penetration - specifically as it pertains to arrow diameter. A smaller diameter arrow with less surface area creates less friction and therefore less resistance as it passes through the animal. Again all things equal - same broadhead, same arrow weight, same bow - the smaller diameter arrow is going to penetrate better.
I don't think you'll have to retune all that much. Aside from your pins being a little farther apart you won't notice much difference.
Sorry, both were shooting FPs. Arrow diameter difference is negligible and arrow mass is very near the same. Not exact of course. Sent from my iPhone using Tapatalk
So I took the time yesterday to look into Dr. Ashbys papers. He raises some good points. The one that stood out that could explain the phenomenon I have experienced is that as FOC increases, the lever arm increases so the forces the fletchings are able to create in stabilizing the arrow are much more pronounced. To add to that point, if the arrow does not require these stabilizing forces (I.e. Seen in a proper tune) low FOC can provide better accuracy (see nose up flight) Digging even further, FOC plays a vital role in penetration and is pronounced when contact with dense objects occur. Having high FOC decreases the amount of flex in the arrow shaft when resistance occurs. So, I have concluded that: 1)decreasing FOC (within a certain range) has potential to increase true arrow flight. It also has potential to decrease true arrow flight when external forces (wind, rain, fog) act on the arrow. 1a)For my setup, I am low FOC based on the standard formula BUT I have a larger lever for the fletchings to act on which greatly improves arrow flight path. 2)increasing FOC increases penetration (as per dr ashby, diameter, BH and velocity are also pertinent factors). 2a) My setup has more shaft to act on in the event of contact with a hard object. That being said, I have a great bit more mass than the typical arrow and with an extremely stiff and small dia arrow I am able to combat this principle (shooting Easton axis 260). This was mainly for my purposes but I hope this provides a bit of insight. My assumptions are based off of my experience with Newtonian physics. I don't have any study data to back these claims. I would however like to compare my FOC calculation with others so I can provide my specs if anyone is interested. Sent from my iPhone using Tapatalk
I love that you took the time to look at Dr.Ashbys reports if you want to learn more about arrows and FOC join the High Momentum Group on Facebook. Also for you I will give you my set up currently. Mathews No Cam HTX 27" Draw 70lb Draw 27" Black Eagle Rampage 300 8.7 grains per inch. 3- Gateway Rayzr Fletchings that weight 1.4 grains as opposed to blazers that are 6 grains each. Regular R nock from BEA= 10 grains Regular half out insert= 54 grains Helix Broadhead 150Gr 50 grain weighted screw in insert behind the half out. These numbers are a touch off from what I posted as those numbers were run with a 26.5 inch arrow. With this im at about 503.1 grains and I lose about .6% FOC
I have found arrows (bolts as well) with low FOC (below 10%) tend to fly by the fletching (vanes) and the reason some can not get fixed broadheads to fly true. As for the OP 25% is a bit excessive but if it works for you shoot on. But if you bareshaft tune your shaft to your bow you will quickly learn how important FOC is. Some times a 1/4 of an inch really changes spine and flight of a shaft or what 25 grains will do. As for penetration there are way to many variables to say how FOC would influence it. COC is best in my 40 + years of experience and heavy better than speed. But since the shaft pert near nevers enter the target on the level FOC would not really come into play.
Bare shaft tuning( provided you have good form) will tell more about what your end results will be in penetrating the target. The quicker that shaft dampens up out of the rest the straighter it will impact the target. Anytime the arrow hits askew penetration will be hampered. Old school FOC was always 8 to 12% until Ed Ashby did his studies on dead African animals( his work was primarily done with a longbow) Heavy FOC can make a good thing better to a degree but, if the arrow is leaving the bow with a wiggle its going to try to force its way through the target the same way heavy tip or not.
I don't think 25 is excessive I would go higher if I could do it but still reach the goals I want to attain with my shaft. Sent from my iPhone using Bowhunting.com Forums
I personally feel higher FOC most certainly has some affect on penetration. Arrow flight, "usually" is a bit better as some stated, because of the stabilization of the arrow. This in turn transfers more energy to the target down range. Secondly, as someone already stated, more weight on the front "drives" the arrow at impact and through the target. The analogy of the 100gr nock is a good one. Take an a straw for example. Push it into a cup lid by the front end, it goes in easily and little to no flex on the straw. Try pushing that same straw into the cup lid from the back end. Chances are the straw will flex and more effort will be required to push the straw through the lid. In arrow land, thats wasted energy. Is its an enormous difference? I do not know. But I firmly believe higher FOC arrows increase penetration to some degree.
