Primitive Archer
Main Discussion Area => Bows => Topic started by: Stick Bender on April 09, 2016, 03:46:04 pm
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I ordered a crony about week ago ,got it yesterday so I decided to test the 2 bows I made over winter the first was a Mohegan style D bow hickory/sinew 62 1/2 ntn with 1 5/16 limbs 50 lbs @29 in was a little disappointed it ran 150fps with 530 gr & 142 fps with 780 gr arrows the next was a wide limb over built maple/sinew 2 in limbs 62 ntn 53 lbs @29 in with the same arrows the 530 gr ran 153 fps & was disappointed again but with the 780 gr shot it threw the crony & it read 160 fps ok false reading next arrow 161 fps rebooted the unit & test booth arrows again & again the bow is shooting heavier arrows quicker then light arrows the only thing I can figure is the heavy limbs are moving slower & with the heavy arrows it's picking up more momentum ?
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Spline?
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i don't think you should be disappointed in the bows at all,, the sinew bows are performing well for the amount of reflex they are holding,, and I am sure smooth to shoot,,
I don't know about the second bow shooting the heavy arrow faster,, but that is a very respectable cast for a heavy arrow from the 53# bow,, the bows are shooting great, you can fine tune for better cast on your next ones for sure,, but both are very good for hunting bows,, :)
yes I guess if the heavy arrow is a better spine for the bow it might have something to do with shooting faster,,if it is coming off the bow smoother,, ??
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I think it is a bad test. The heavier arrow should have been at least about 25 to 30 feet per second slower than the lighter arrow. I can't think of any feature that would let a heavier arrow shoot faster. Try a retest and make sure there are no overhead wires nearby.
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Back in the mid 90's I went through the speed thing. Don't thing ,no I know I've never did the crono thing again.
I must have shot 10 of my own self bows at the time. My fastest self bow Osage 67" 61#@26'
It shot a 600 grain arrow at 179 fps.
From what I learned the saying right add your wait to 100. It'll be with 5 fps. Try that crono out some more. Make you own assessment.
I've built unteen bows since then they all look fast enough to me.
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Thanks Badger that makes sense I did the testing in my shop because it's been raining here ,all kinds of wires around ,will retest next week end
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I could see how a heavier arrow could shoot faster than a light one, certain factors were right. If the light arrow was a weaker spine weight it would absorb more energy with a bigger bend stealing it from the cast. If the heavy arrow was the perfect spine for the bow, no extra energy would be lost in excess bend. It would be delivered to the cast of the arrow and should go faster. If you were to go heavier still, I would expect the fps to drop off as expected. I can't imagine this scenario happens often, but I can see how it could.