Trad-Bow arrow speed & KE

[tombow]

#3792

In my never ending quest for more information to cram in to my feeble brain, I am looking for input from my more experienced trad “brothers and sisters” on arrow speed and KE. I am shooting a Toelke Whip 62″, 53 @28 and drawing right around 28″ or a titch more. With MFX 500’s, 125 gr. head, 75 gr. insert, total weight at 505 gr., FOC about 16%, I am getting 175 fps. With my recent endeavor with wood, total arrow weight of 545 3 fletch, 552 4-fletch I am getting the same 175 fps, FOC a bit under 10%. KE seems to calculate to upper 30’s. My experience with KE studies has been compound related where I was getting double KE compared to trad shooting equipment. Is something askew (other than my brain) or am I getting what I should with my equipment? Please let me know if the above seems either “’bout right” or “yer gettin’ WHAT?”

Thanks. Traditional archery has me swirling in the whirlpool and is drawing me in deeper and I have a BIG smile on my face! You can probably relate!

[Arne Moe]

#23740

Tom,

You are getting what you should be. KE is largely a function of velocity. K=mv^2. The velocity is squared so the much higher arrow speeds of a C bow produce much higher number for KE. Most of us “trad” shooters discount the KE values in favor of momentum to measure arrow performance. M=mv. Your numbers on your Whip are about right and more than enough for hunting.

Some (myself included) will say that the KE figure is really a C bow’s manufacturing advertisement hype. By squaring the velocity, and as you notice they get much higher and therefore more impressive numbers to advertise with. They did what you are doing to show the much higher KE for the C bows as compared to “trad.”

Arne

[David Petersen]

#23790

Thanks for covering the tech aspects, Arne. I can only emphasize that when applied to hunting KE means almost nothing as an indicator of penetration and killing power, since a typically very light high-KE arrow’s speed comes to almost a full stop as soon as it hits flesh or bone (especially if using some of the lousy broadheads marketed to compounders these days, particularly mechanicals), crumbling that speed-squared bragging figure to almost nothing in far less than a heartbeat. To the contrary, a heavy arrow (high momentum) with the right broadhead (one that holds together and minimizes friction in passing through tissues, esp. heavy bone) retains far more of its energy and forward momentum on impact with flesh, providing greater penetration and lethality even though shot from lighter bows with lower speeds. In sum, speed helps but it’s a false god to pray to for max penetration and lethality. That is the standard traditional view, as proved out both in the Ashby studies and in the field every fall. You’ll know you’ve successfully made the transition to traditionalist worldview when you no longer worry about speed and no longer even think about KE.

[Jason Wesbrock]

#23867

Moebow gave an excellent explanation as to the difference in Ke between compounds and stickbows. In answer to your question regarding your particular numbers, they seem about right to me for a bow drawn 28″ shooting around 10 grains per pound. Hunt with confidence; it sounds like you have a nice setup.

[Dan Sweeney]

#24499

Make a really heavy arrow, put a sharp head on it, make sure you can hit with it, and send the rest of that mumbo-jumbo back to Cabelas.

[tombow]

#24826

True my previously less knowledgable mind has been turned askew by being bombarded with “KE”, less so with speed. The (to me) numbers shown in the advertisements for the new compounds, relative to speed, are ridiculous overkill. Sure all bowhunters, regardless of tackle, want to make a quick clean kill. This is the reason for my questions, as I have come from the C bow world where there is enough KE to penetrate a refridgerator and the arrow will be there before you hit the trigger on your release. It is the lack of experience on my part concerning traditional archery harvests which makes me grasp at the straws of KE, something about which I have some knowledge and a bunch of experience with harvests. I do find myself moving from the technical into the more philisophical mindset as my traditional career evolves. Bottom line: I want to do my best to make a quick kill when I chose to wield my weapon of choice toward a game animal. When that has been done, then I will enjoy the “meat of the matter”, both physically and philisophically. Thanks for all your input. Sometimes I ask questions which I have an inkling of the answers to but it helps when those answers are fortified by the knowledge of others with more experience than I. Again, I thank you all.

[tombow]

#29288

Update: My head was spinning after sifting through all the Ashby library, reading about EFOC, etc. I plan on doing some more testing with some older arrows that I can get up to 21% FOC, whose dynamic spine closely matches the wood arrows I recently put together that fly so well I almost am ready to commit fully to those and put the carbons aside. Just not quite yet. I will be mounting a “donated to the TomBow cause” Grizzly’s on my wood shafts and watching for flight. For me, it’s just the matter of lack of experience with trad.bow kills that has me questioning my set-up. But that IS the ultimate mystery until I see what good flying arrows will do when a whitetail gives me an opportunity. Theories are interesting to think about but I need first-hand experience to say “This is my arrow set-up” and stick to it. Thanks again to everyone who took the time to share info with a trad noob like me. Ya, I know some stuff but there’s some questions that I still need answered. The compound taught me a lot but the satisfaction of instinctively putting the arrow where I am looking has re-lit my bow pleasure level to new heights. Perhaps it is my need to learn more that has me so pumped up. Love my Whip, Love my new arrows. Jeez, I’m just all full o’ love me Bow-Sisters and Bow-Brudders!!

For me, it’s all about the TRADBOW family campfire! Sit down, crack a cold one and let’s talk bows and arrows! Can’t get enough!! And I’m sure I never will.

[Author]

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