115 plus bow weight = f.p.s . ?

[Jim Wright]

I recently saw another bowyer in addition to Howard Hill Archery use the formula: 115 plus draw weight equals f.p.s. that a customer might expect out of their bows. My own Hill Style 52 lb. bow chronographs 520 grain arrows the same as my 58 lb. does 580 grain arrows. They do the same with 12 to 1 arrows of course, as do my other style bows when comparing different draw weights. I would expect the same results from a Howard Hill Long Bow and don't understand how this formula could pan out, simply out of curiosit am I missing something?

[Rob DiStefano]

on the business of bow and arrow speed ...

first and foremost, arrow speed doesn't kill.  

well placed, well flying arrows with sharp broadheads are the proper ticket to that dance.

those kinda speculative, projected arrow speed  formulas aren't even worth messing with, as the technical rubber meets the road with a proper chronograph and you'd be surprised sometimes at the results, particularly when a finger release is used and not mechanical. however ...

in the long run, the actual, technical arrow speed doesn't mean anything at all.  not a thing.  

read that again!  yes, it's true!  all that matters is figuring out, via *your* testing, the best flying arrow for yer bow and *you*.  keep the arrow weight reasonably high (9-10gpp at the minimum), and stick within yer comfort shooting distance zone for arrow trajectory and yer good to go!  
 
now go kill something for suppers!  :D

[YORNOC]

I'm no expert, but I have seen three different chronographs at a summer tournament show three different speeds of the same bow/arrow combo. One showed a difference in speed each of the three times it was used.
Not saying that your chrono is off, but it could be a possibility.

[Jim Wright]

David I have observed the same thing with different chronographs and variations in readings with the same chronograph/shooter/set-up is an indicator of improper form, particularly an inconsistent release. My question is still out of curiosity and is how can 115 plus poundage equal f.p.s. ?

[Rob DiStefano]

i've also witnessed, and been part of, chronographing bows/arrows using as many as 4 different chrony's at the same time, all yielding different readings when finger released, while all showing about the same numbers using a mechanical release.

really, what does all of that matter?

why even care?

long since sold off all my chronys ... a waste of time for me.

[Shaun]

I believe that formula of 115 + draw weight refers to shooting a 500 grain arrow - not 10 grains per pound of draw weight. If you use a proportionally heavier arrow you will only see a difference if the efficiency of the bow increases - which is not a function of draw weight.

[ArrowAtomik]

Its just his personal rule of thumb, nothing more. It is not a magic number. Obviously there is far more to it.  I would not trust it more than within 20 fps, even if the setup does fall into "the norm" that he used to come up with it. Probably for that bowyer, drawing his bows, with a certain gr/lb, he determined it to be a formula for decent estimation.


Someone with a 50# bow that draws 24 inches does not get the speed from a 50# bow at 30 inches.  One of my crappy selfbows does not get the fps of a high performance bow.  A poorly spined flu flu does will not chrono the same as a perfectly spined bare shaft.  An awful pluck release and perfect form... etc.
There's much more to it.

[Jim Wright]

Rob, you make a good point, especially your last question and I'm pretty sure I know the answer already to my own question. I would add that I totally agree with your advice concerning arrow weight and sticking to shooting distances that we are consistently efficient within.

[Jim Wright]

I would offer that the reason I have chronographed my bows is that I shoot quite a bit of 3d and like to keep my arrow speeds with different bows within 3-4 f.p.s. or less of each other. For example, my Toelke Super D Hill Style shoots 10.5 to 1 the same as my extremely quick Curlew take-down recurve does 12 to 1 arrows. My Whips shoot the same at 11 to 1 and the short story is, I find it easy to shoot multiple bows at 3d or hunting with the same arrow flight/trajectory. To me there is an advantage in never having to re-set the "computer between your ears".

[Pat B]

I shot one of my selfbows through a chrono once and was so disappointed with the number I never did it again. I have no problem with the way my selfbows shoot. I'm sure they will do the intended job if I do mine!

[Rob DiStefano]

Originally posted by Pat B:
I shot one of my selfbows through a chrono once and was so disappointed with the number I never did it again. I have no problem with the way my selfbows shoot. I'm sure they will do the intended job if I do mine!

+1        

i really dislike getting too techno with stick bows.  it's enuf to deal with glass backing and facing on limbs, carbonium/aluminum shafts, and poly-whatever strings.   :D

[SEMO_HUNTER]

The formula mentioned above does not work with my setup. I also shot my Bear Grizzly through a chrono one time with my 500gr. arrows and was a bit disappointed.
I never intend to do that again because it really doesn't matter to me how fast or how slow, but where I can put that broadhead makes all the difference.

Just food for thought, the Indians rarely shot bows over 25-30lbs. with sticks and rock points and they took down Buffalo very efficiently. Of course their shots were very close range and sometimes from atop a horses back so the angle of their shot was downward into the spine. Their mentality was to disable the animal first and put it on the ground, then finish the job once it's immobilized if need be.
However they accomplished the task, it was done with far less than what we have available to us nowadays with highly efficient bows, straight arrow shafts, and razor sharp broadheads.
At least that makes me feel better when I think about it in those terms.

The chrono testing did one thing for me.  I found that if I have a clean hard release, the speed was about the same as my mechanical release.  If I used a comfortable lazy release, I could loose 8 to 10 fps.  What I discovered doing this is that my longer long bows had less overall speed than my BW recurves, but also had less difference in arrow speeds with the varied releases.  With cedar arrows my current bows shoot faster than the 115 plus bow weight, it is nothing to think about until one is dealing with lower poundages and comparing one bow that would maybe not have enough zip to do its job to one that would put out a faster arrow at a lower poundage, while keeping the arrow weight the same.  A fast 50 pound bow may be a better choice for moose than a dead slow 60 pound bow shooting the same weight arrow, especially if one has trouble shooting the 60 pounder.

[pdk25]

Originally posted by SEMO_HUNTER:
The formula mentioned above does not work with my setup. I also shot my Bear Grizzly through a chrono one time with my 500gr. arrows and was a bit disappointed.
I never intend to do that again because it really doesn't matter to me how fast or how slow, but where I can put that broadhead makes all the difference.

Just food for thought, the Indians rarely shot bows over 25-30lbs. with sticks and rock points and they took down Buffalo very efficiently. Of course their shots were very close range and sometimes from atop a horses back so the angle of their shot was downward into the spine. Their mentality was to disable the animal first and put it on the ground, then finish the job once it's immobilized if need be.
However they accomplished the task, it was done with far less than what we have available to us nowadays with highly efficient bows, straight arrow shafts, and razor sharp broadheads.
At least that makes me feel better when I think about it in those terms.

Not sure that I would consider that great efficiency.  Just using what they had. I bet those bison looked like pin cushions and that more than a few died much later without being recovered.

[Ben Maher]

I used a chrony for my Fita tackle , but once I used them on my hunting bows , I saw just how slow my bows were. So I stopped using them altogether and took those same ol' slow hunting bows and went and killed a bunch of critters.

If I had paid attention to the chrony to much I would have really doubted my tackle ...

The 115# plus bow weight is an optimistic guide IMHO

[Rob DiStefano]

Originally posted by SEMO_HUNTER:
... Just food for thought, the Indians rarely shot bows over 25-30lbs. with sticks and rock points and they took down Buffalo very efficiently. Of course their shots were very close range and sometimes from atop a horses back so the angle of their shot was downward into the spine. Their mentality was to disable the animal first and put it on the ground, then finish the job once it's immobilized if need be.
However they accomplished the task, it was done with far less than what we have available to us nowadays with highly efficient bows, straight arrow shafts, and razor sharp broadheads.
At least that makes me feel better when I think about it in those terms.

as a 21st century trad bowhunter, none of that makes me feel better or should even be entertained.  

30# stick bows, stone points and buffaloes just don't cut it for me.  the 19th century indians killed to survive and some of their methods would be ethically questionable in today's society, but surely not in theirs.    

imo, indian hunting tools and methodologies are not up for comparison with today's breed of stick bow hunters.  both are very very different in so many ways, and our goals are somewhat different.

ymmv.

[Rob DiStefano]

Originally posted by Ben Maher:
I used a chrony for my Fita tackle , but once I used them on my hunting bows , I saw just how slow my bows were. So I stopped using them altogether and took those same ol' slow hunting bows and went and killed a bunch of critters.

If I had paid attention to the chrony to much I would have really doubted my tackle ...

The 115# plus bow weight is an optimistic guide IMHO

as usual, ben, you have words of wisdom that ring true to my old ears.

[David McLendon]

quote:
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Originally posted by SEMO_HUNTER:
The formula mentioned above does not work with my setup. I also shot my Bear Grizzly through a chrono one time with my 500gr. arrows and was a bit disappointed.
I never intend to do that again because it really doesn't matter to me how fast or how slow, but where I can put that broadhead makes all the difference.

Just food for thought, the Indians rarely shot bows over 25-30lbs. with sticks and rock points and they took down Buffalo very efficiently. Of course their shots were very close range and sometimes from atop a horses back so the angle of their shot was downward into the spine. Their mentality was to disable the animal first and put it on the ground, then finish the job once it's immobilized if need be.
However they accomplished the task, it was done with far less than what we have available to us nowadays with highly efficient bows, straight arrow shafts, and razor sharp broadheads.
At least that makes me feel better when I think about it in those terms.
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Not sure that I would consider that great efficiency. Just using what they had. I bet those bison looked like pin cushions and that more than a few died much later without being recovered.
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Agreed, and they also weren't opposed to driving them off cliffs and probably more frequently than is mentioned a few braves didn't survive the hunt from time to time.

[Covey]

I for once agree with Rob!! What does it matter? Jason