Arrow speed test

[gundog]

I was doing some cronograph work and was wondering how much deveation would normally occour shot to shot. What would be acceptable ?Recoil pressure is the factor that I have trouble with. How many arrows need to be shot to get the info needed? Any tricks of the game would be appreciated.

[Big John]

Not sure exactly what your looking for, but myself, I would shoot say 100 shots
then take the average of them. I would say pretty accurate measurement.
I might add, I have seen the same arrow, shot with same bow, thru same chrony,
10 times and got 4 different readings. Thats discounting any tenth's or other, strictly
exact F.P.S.

John

[sumner4991]

I agree with John . . .except on the 100 shots . . .depending on the weather conditions, you can get a good reading after 10-15 shots. Doing 100 shots will definitely get you a reading that you can take to the bank, but, typically, it will differ very little from the 10 shot average.

It's best to do the test when it's cloudy, the chrony will read better.

The string material will effect the consistancy too. Dacron will have more of a speed range or deviation than Fast Flight. The stiffer the material, the more consistent the speed.

A string that has been shot several times is more consistent than one right out of the package.

Speed ranges . . .typically, I get a two FPS variance. There will be an occasional 5 or 6 FPS "flyer", either high or low . . .and sometimes an odd 8-10 FPS. I've had a couple of strings that hit the same FPS on just about every shot(same arrow, same bow, same spot of the target).

[bob1961]

when you guys shoot through a chrony does it matter how high or low through the wings or triangle you need to....other words will you get two different readings shooting high or low or it don't matter.........bob

....

[Normous]

I find my Competitive Edge Dynamics Chronograpgh to be very arrow friendly and consistant. My arrow variation has an extreme spread of 4 fps on some days. The standard arrow variation I find is about 2 fps. High or low shots through the screens makes no difference. I shoot one foot from the start screen.

[Joystyx]

Crossbow shooting geeks, unite under this post
/purr

[Limbs and Sticks]

when you guys shoot through a chrony does it matter how high or low through the wings or triangle you need to....other words will you get two different readings shooting high or low or it don't matter.........bob

....

I've got a F-1 chrony, in order to get accurate readings bullet or arrow must be between 4 to 6 inches above the eyes [front and back] with a bow shoot at arrows length from chrony, 20in xbow for most, hope this helps you

Wes

[bob1961]

thx guys ........bob

....