Chrono results

Discussion in 'General Archery Forum' started by Cameron, Aug 19, 2007.

  1. Cameron

    Cameron Senior Member

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    I am always amazed at the chrono results I see posted on the different forums. Folks always wondering why their $800 bow is shooting 20 fps slower than "what it should be".

    Now I am no expert, but I have learned a few things about chronographing projectiles from my hand loading ammo, and competitive pistol shooting for the past few years. I have had the oppertunity to learn that chrono is not an exact science, and how to best eliminate error in readings. So I figured I would share what I have learned after shooting through dozens of different chrono's across the country.

    To get the most accurate readings possible from your bow, try following the following guidelines.
    1. Buy a high quality chrono, not the $69.00 model
    2. Fresh batteries, or a 110v power source preffered.
    3. The chrono light source should be infared.
    4. The chrono should be put in a "coffin" so no ambient light will have an effect on the lighting conditions
    5. Keep all arrows flying through the skyscreens level to the sensors, about 4 inches above the sensors, and consistanly in a 1-2 inch circle through the circles.
    6. Shoot 3 arrows at a time and take the average.

    I can consistantly demonstrate that readings using this process will yeild 10 fps higher than shooting through a chrono on a sunny day, and 5 fps faster than using a light bulb setup on the skyscreens.

    The truth is, unless you have a speed "standard" you can shoot through the chrono, one can expect a =/- 10 fps error in readings.
     
  2. beenfarr

    beenfarr Senior Member

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    Good info! Thanks.

    Ben
     

  3. Dredly

    Dredly Site Guru

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    or it could be a much simpler solution....


    manufacturers lie in order to boost their advertised rating so that they can sell more bows, speed sells. They blame the lack of people meeting the actual speed on the shooter, the bow being out of perfect tune, the chrono, the arrow, the string, items on the string... etc. Bows are not shipped tuned, the manufacture doesn't care about THAT portion of the bow.

    In reality its the same as MPG in cars... yeah you CAN get this MPG if you drive at exactly 57.9 mph on a perfectly flat surface after driving 25K miles to break in the engine and using precisely the correct oil, gas, engine components... etc
     
    Last edited: Aug 19, 2007
  4. Cameron

    Cameron Senior Member

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    True Dredly. I was really not poking at the OEM bow builders though, just commenting on how everyone runs down to the bow shop to chrono their bow, and call it golden numbers.

    I will add though, my Guardian did shoot BC speeds through my infared setup.:rockon:
     
  5. BowTechArch

    BowTechArch Senior Member

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    Just to add some more tips:

    1. If you use your chrono outdoors; wait for a cloudy/overcast day.

    2. The highest velocity will be seen when your drawn arrow's tip is approximately 3 - 4 feet from the 1st screen. [At least an arrow and a half distance].

    3. DO NOT shoot near a florescent light source.

    4. Make sure no shadows are cast upon your chrono's screens.

    5. DO NOT shoot your chrono!!!
     
  6. BUNNYMAN

    BUNNYMAN I pray for you!

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    for any reason at all????what if there is a bug on the lcd screen???


    these are all very awsome points and i will be trying them.....
     
  7. BowhuntnHoosier

    BowhuntnHoosier Bisquit.......

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    Hey whats wrong with the $69.00 version??? I so poor I can't even pay attention to the thread topic.:doh:
     
  8. Cameron

    Cameron Senior Member

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    Now that's funny right there...
     
  9. IChim2

    IChim2 IChim2 and he's a shooter

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    Agree.but i think a lot of archers have complained enough through site's that the companies are starting to be a little more honest with their IBO's...maybe
     
  10. J.C.

    J.C. New Member

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    I think I'm gonna buy a Radarchron that screws into your stabilizer bushing. It doesn't use lights and I've heard it's very consistent. Anyone tried one?
     
  11. brokenarrow

    brokenarrow Evil Genius

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    Nope...:noidea:
     
  12. Pinwheel1969

    Pinwheel1969 #1 THREAD KILLER

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    Totally correct. Thats why I always shoot before a tourney. qualifier. All wont give same results. Though I bought the new Easton Mapping system. Which cam with there top chrono. Its dead nuts. Best one I've used or seen yet. Angles dont change speeds like the cheapo's do. And have found a few manufacturers w/ really inflated ibo ratings. LOL:Cry:
     
  13. BowTechArch

    BowTechArch Senior Member

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    Consistent? = No

    Tried One? = Yes


    I think their error percentage is 3%

    let's see......3% of 300 fps = 9 fps........:noidea: :noidea:
     
  14. Dredly

    Dredly Site Guru

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    I have to sort of disagree. We used these extensively in paintball and they were extremely accurate. Normally within 1 fps of the big expensive chrono. I'm not sure if they are the same with bows or not but I don't see why they wouldn't be.

    For almost every archer out there +- 3% is still good enough :) and at 70.00 it works great and is very portable
     
  15. beenfarr

    beenfarr Senior Member

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    9 FPS is a big deal when you use a slider sight, and print sight tapes. At 40 plus yards, you'll really notice it.

    Ben
     
  16. Dredly

    Dredly Site Guru

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    true... but how do you know if the reading you are getting is correct off you other chrono?
     
  17. BowTechArch

    BowTechArch Senior Member

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    Shoot your setup through at least 3 different chronos....

    I know of 3 of my current bow setups that shoot within 1 fps on 3 different chronos.

    (1) Chrono = Crackers

    (1) Chrono = Easton Chrono

    (1) Chrono = My personal ProChrono