Arrow speed

[Brad sturgeon]

I’m not about speed but every bow I make regardless of design seem to shoot about 127 fps.i see all over utube self bows shooting 150 plus fps . I make about all of my bows with Osage and I can kill deer with them but I don’t understand how people get speeds so far ahead of mine. I’m shooting 560 grain arrows at 50 lbs 27 inch draw. Unless Chronograph I bought if not accurate they all shoot 125 to 129 both recurve and longbows. The Chronograph shows 140 arrow speed on a Jeffries take down using the same arrows at 51 lbs on the bow. A ny insight would be great. Thanks

[Mo_coon-catcher]

Can you post any pictures of your bows? Unbraced, braced, drawn and unbraced front profile? It can give some insite. And how you tiller can make a difference as well too. How long has the wood you’ve been using been drying?

Kyle

[Roy from Pa]

Think I would try a different chronograph.

[Stagmitis]

The industry standard for speed testing is a 10gpp arrow drawn to 28”- you need to start there. What crony do you have? Like Kyle suggested post pics of your bows- also make sure you have an accurate scale and get the correct weight of the bow at 28”

[Mo_coon-catcher]

One other factor I remembered that comes into play. Make sure you’re actually coming to full draw when shooting through the chrono. With the same bow arrow combo, you will see about 10fps for every inch change in draw length: the times I’ve seen those numbers you’ve show. Is when someone draws a bow intended for 28” draw only to 23” or so. When I built a bow for a 27” draw and I actually pull to 27” I’ll see between 160-170fps, if I short draw an inch I’ll see 10fps lower.

Kyle

[Brad sturgeon]

How do post a picture

[Mo_coon-catcher]

Right here in the circle. Atleast for phone anyway. No idea for computer as I havnt posted from a computer in years.

Kyle

[Kirkll]

Shooting though a chronograph is a fickle beast. The lighting alone can throw your results way off. A cloudy day, vs direct sunlight, and shooting in a shaded area can all give different results.

Something sounds off to me... An Osage bow at 50# with a 550 grain arrow should be faster than 127... i'd guess it should be at least 160 with a 27" draw, and higher at longer draw lengths.

I'm not into chasing speed much any more, but i was into it big time years ago, and used it a lot while prototyping different limb designs. The only consistently accurate  speed testing i found was setting up a light kit and using a shooting machine indoors... btw... do NOT use under florescent light fixtures. Incandescent lighting or LED lighting only.  Here is the light kit.

 https://www.opticsplanet.com/caldwell-chronograph-light-kit.html

At one time i had a testing set up with two chronographs back to back that i shot through to confirm the accuracy. Measuring exact draw weight and draw length, & matching it on the shooting machine is critical. And weighing arrows is critical too. The most accurate tests are done with bare carbon shafts and black field tips... Even a shinny field tip can throw your numbers off a bit.

Shooting through a chrono by hand just using fingers, you will get a lot of variables and different readings. The same bow shot by a different archer will get different results too even in perfect conditions with identical draw lengths.    hope this helps...  Kirk

[Brad sturgeon]

Thanks to all who commented. Since I posted I went to a shop and shot through their chronograph and it showed 140-144 arrow speed that mine showed 127.Then I got mine and went out in sunlight and got 2 good readings out of ten shots. I think the chronograph I have is faulty. Exact arrow shot was 560 grains 26.5 draw 49 lb.i posted three pics of this bow if they go through . That still seems a little slow but it did feel a little better not to be 127. I just hunt and not concerned with speed but do want to make the best bow I can. Thank you all

[Brad sturgeon]

Attachment

[Brad sturgeon]

Attached

[Kirkll]

It’s really tough to get good numbers even from a glass backed or carbon backed lam bow at shorter draw lengths. A shorter bow with a short working limb section is about the only way to pull it off. Also having a limb design with minimal limb travel helps a bunch.

But…. Once you start getting into higher draw weights. Say 60-70 pounds. You’ll start seeing a significant increase in performance at shorter draw lengths.

With glass backed bows, the mass weight in limbs is much less than a self bow, and you’ll see much higher numbers. Reaching 170- 180 fps at your specs is very possible.

[Longcruise]

I shoot a lot through chronograph and the second I saw your results with the Jeffries I knew it is your chrono. 

Contact the manufacturer and see what they have to say.

[Pat B]

Having the bow quiver mounted on the working portion of the limb could slow the bow down considerably.

[Kirkll]

Having the bow quiver mounted on the working portion of the limb could slow the bow down considerably.

Pat.....You really think that fade area is storing that much energy to effect performance? I'm not seeing that myself...