short draw chrono results

[bradsmith2010]

    a few threads ago some expressed interest in short draw performance,, I took some notes making bows a while back,,and found sometimes the shorter draw shoots harder than some would think so am looking at my notes to post a few results,,,I did find that shooting the bow through a chrono even at very short draws gave me a good indication of what a bow might do at desired draw,,
    my first example is from 2016,, its an osage bow,, stave bout 10 years old,, length 69 inches,, intended draw for a friend(jeffer) 29 or 29 1/2,,, I posted this bow but cant remember the name of the thread,,it says in my notes the stave was holding 3 to 4 inches of reflex,,
    ok first test the bow was 44#@20 inches,,,148fps with 480 grain arrow,,,
    then as I tillered it out,,49#@22 inches 156 fps with 486 grain arrow,, you can see the bow shooting harder with increased power stroke,, ok at 24 inches of draw,,53#@ 24 inches and 486 grain arrow  167 fps,,,
    ok even though the bow is really to long for a short draw,, it is showing that it could shoot a hunting weight arrow very well,,at this point I put a rawhide back on the bow,, and it still performed very well out to the 29 inch draw,,but could have made a nice shooting bow from 24 inches out,,, I have found that alot of bows in the tillering process start to shoot really well once to 24 or 25 inches of draw,, and at that draw are under very little strain.. or not taking much set,,, ok thats the first example I have some more notes of some sinew bows,, that I will post later,, if anyone can tell me how to find that post I would like to see it,,
    I wanted to add, that alot of the time we are disappointed in the results,, its not because of the process or skill,, but wood can vary sometimes and its about the material,, or string,, or moisture content or other factors,, not the process or skill,, this stave is a great example,, the natural reflex really helped ,,,Im not sure if heated in reflex is as effective,, anyway,, just saying for new guys, dont be so hard on yourself,, guys getting consistant great results have worked decades,,,to achieve that consistency,, and know how to pick wood that will do it,,

[PaSteve]

Interesting subject Brad. My draw is about 25 1/2" with natural bows so I'm very interested in your findings. I'll agree that a particular stave can make the difference. The Osage bow I usually hunt with definitely has an velocity edge over other Osage bows I've built of similar design.

[bradsmith2010]

I think it is so interesting,, I have a black locust bow that shoots about 150 at 20 inches of draw,, its really short all the wood I had,, holds only bout 1 inch reflex with thin layer of sinew,,,it would kill a deer,, if I could hit one with it,, Ill post a photo later,,

[Badger]

 That was a very interesting post Brad and mirrors what I have observed. My draw is 26" I am comfortable at 25". That's where I will start tillering them to.

[George Tsoukalas]

Brad, very nice post. Jawge

[bassman211]

150 fps is plenty fast to kill a deer with a 400  to 450 gr arrow.  I have mentioned this before on here , but it bares mentioning it again. Just this year my son killed a nice buck with one of my horse bows. It chronied 135 fps with his bow arrow combo. It is a string follow bow. He shoots it accurate at 15 yds. He killed the buck at 11yds.  The arrow penetrated 11 to 13 inches in the vitals, and the deer expired with in 60 yds. Shot placement trumps speed ,but when you have both you have a real winner.

[bradsmith2010]

yes that deer was better test than a chrono,,
thank you Jawge and Badger,, Im gonna post some more results going over the notes now

[Selfbowman]

    a few threads ago some expressed interest in short draw performance,, I took some notes making bows a while back,,and found sometimes the shorter draw shoots harder than some would think so am looking at my notes to post a few results,,,I did find that shooting the bow through a chrono even at very short draws gave me a good indication of what a bow might do at desired draw,,
    my first example is from 2016,, its an osage bow,, stave bout 10 years old,, length 69 inches,, intended draw for a friend(jeffer) 29 or 29 1/2,,, I posted this bow but cant remember the name of the thread,,it says in my notes the stave was holding 3 to 4 inches of reflex,,
    ok first test the bow was 44#@20 inches,,,148fps with 480 grain arrow,,,
    then as I tillered it out,,49#@22 inches 156 fps with 486 grain arrow,, you can see the bow shooting harder with increased power stroke,, ok at 24 inches of draw,,53#@ 24 inches and 486 grain arrow  167 fps,,,
    ok even though the bow is really to long for a short draw,, it is showing that it could shoot a hunting weight arrow very well,,at this point I put a rawhide back on the bow,, and it still performed very well out to the 29 inch draw,,but could have made a nice shooting bow from 24 inches out,,, I have found that alot of bows in the tillering process start to shoot really well once to 24 or 25 inches of draw,, and at that draw are under very little strain.. or not taking much set,,, ok thats the first example I have some more notes of some sinew bows,, that I will post later,, if anyone can tell me how to find that post I would like to see it,,
    I wanted to add, that alot of the time we are disappointed in the results,, its not because of the process or skill,, but wood can vary sometimes and its about the material,, or string,, or moisture content or other factors,, not the process or skill,, this stave is a great example,, the natural reflex really helped ,,,Im not sure if heated in reflex is as effective,, anyway,, just saying for new guys, dont be so hard on yourself,, guys getting consistant great results have worked decades,,,to achieve that consistency,, and know how to pick wood that will do it,,

All true Brad.

[Selfbowman]

Steve I liked your design on the short bow your building.Ive found the longer bows do better with the added draw length in the broadhead distances. But in flight Short bows seam to Do better. Steve it might have something to do with what we have noticed in the past where set starts raising its ugly head at about 22-24”. So if we make the short bow with no set and put a light arrow in it the Majic happens. I have been after flight records for years with the longer bows to no avail. So this next year my flight bows are going to get shorter. Please keep the results coming.

[mmattockx]

Thanks to Brad for posting that info, it really helps to build up the knowledge base with actual numbers on these things.


Mark

[Chumash]

Real Tested

55l bs/ 26 Osage recurve  with bamboo backing  (53" bow length) with a 8,5 gpp arrow 175fps.

45 lbs / 27 deflex static recurve Ironwood with ash backing by MSL (60" length) with a 10gpp arrow:  180fps

55lbs / 27 Osage recurve sinew backing (56" length) with a 9gpp arow: 175fps

55lbs / 26 Osage selfbow by K. Vögele (58" length) with a 9 gpp arrow 183 fps

45lbs / 27 Hickory selfbow (59" length) with a 10gpp arrow 170fps

The last two years I have shoot the Hickory selfbow and I enjoy to hit the target more than to shoot fast in the nirvana....

and with a good  fitted arrow I hit the target with all bows.....

[bradsmith2010]

thank you Chumash,, for that great info,, I appreciate the effort to post for us,,
    ok here is my second example,, the bow is not that fast,, but I did start shooting at 20 inches of draw and have some notes on it,, it was from a belly cut osage that was a little ragged, ,and I was not sure it would even make a bow,, it was about 1 inch wide,, I put rawhide on it because some of the edges looked bad,, but didnt have enough wood to rasp them smooth,, ok
     the bow was 56 inches knock to knock  with rawhide back,, in my experience the rawhide didnt really slow the bows down, I think the string you use has more effect on that than a good thin backing,,in this case I dont think this peace of wood would have made a bow without it,,
     54#@ 20 inches and would shoot a 500 grain arrow 144 fps,, this is with b50 string,, never tested it with fast flight that I can see
     59#@23 inches 151 fps with 500 grain arrow
     60#@25 inches 170 fps with 500 grain arrow,,
     sometimes I got lazy and didnt bother to make an arrow that was 10 gpp,, and back in the day, most people shot a 500 grain arrow cause that was what Tim was shooting in the design chapter,,
      but a hunting weight arrow going 170 fps is really deadly,,i still have this bow I made it in 2015,, it has taken some set and I think its probably lost some speed,,but shoots well,, the width of the bow just wouldnt handle the 60#,, just not enough wood there,,thats how we learn,,

[mmattockx]

     59#@23 inches 151 fps with 500 grain arrow
     60#@25 inches 170 fps with 500 grain arrow,,

This really demonstrates the effect that a longer draw has. Only a 1# weight increase, but almost 20fps more speed with the same arrow. Do you have any pictures of this bow?


Mark

[bradsmith2010]

Im looking at my notes,, it does seem like I made a mistake,, somewhere, ,but the the final weight is 60# at 25,, maybe I overdrew the bow on the last measurement,, not sure, but thats what I wrote down,, maybe I had swithed to a fast flight on the last shot something,,  I have in my notes that I re tested the bow again on june 26 with 478 grain arrow(first test was november,, so several months later) and it shot 170fps,, so I have a feeling it might be a combination of how far I pulled the bow,, and accurate weight etc,, shooter error,, 
yes I have a picture of the bow,, let me find it
    Ok I have a feeling that when I pulled it to 25 inches,, it had not been shot much at that draw,, so was a pretty fresh reading,, and probably settled in to a less dramatic increase,, I dont have that in my notes,, but have a feeling that accounts for some of the increase,,Maybe my releasse was better that day,,

[bradsmith2010]

bow pics