Guesses on muzzle velocity, 300 RUM

Discussion in 'Reloading' started by Crop Damage, Dec 5, 2009.

  1. Crop Damage

    Crop Damage Well-Known Member

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    I'm very, very new to reloading. I do not have a chronograph, I could probably use one if I called several people. I've got a hunting load that's working really well for me, and I'm not sure what kind of velocity I'm getting. Was hoping some more experienced people on here might have some better guesses at it than I do. Trying to make a rough ballistics card out to 700 yards.

    Load is

    300 RUM
    190 Berger VLD Hunting Bullet
    88.0 gr 7828
    Rem Brass
    CCI Magnum Primer

    Rifle is Remington 700 APR w/ 26" barrel
    Temps average 50 degrees
    About ten feet above sea level, on the high ground.
     
  2. lazylabs

    lazylabs Well-Known Member

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    I would just shoot to make your card rather than guess a velocity and hope your getting the BC as advertised. I have never had great luck basing drop strictly off MV and calculated values.
     

  3. ROBSTER

    ROBSTER Well-Known Member

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    180 swift with 88.6 grains of 7828 are 3100 with a 26 inch barrel hope this helps or gets you close
     
  4. Varmint Hunter

    Varmint Hunter Well-Known Member

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    I'd add that when you actually shoot at the extended ranges you will have a MUCH better idea of what the accuracy of your load is at that distance. 1" @ 100 yards does not equate to 7" @ 700 yards. Not anywhere except on the web, that is. :D

    Many shooters are limited to load testing at 100yds - 200 yds and make assumptions as to bullet drop and group size at all other distances. Actually shooting at these distances often tells a whole different story.
     
  5. boomtube

    boomtube Well-Known Member

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    "Was hoping some more experienced people on here might have some better guesses at it "

    Sorry, anyone with any useful level of experiece knows better than to attempt that.

    The others are correct, actual shooing is the better way to find your tragectory and much more accurate than any educated guesses, even when computed from a properly measured speed.

    Exerienced hands know it really ain't as simple as computer ballistic programs would lead us to believe.
     
  6. jwp475

    jwp475 Well-Known Member

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    No way to guess the velocity accurately. 2 different rifles shooting the same load can give very different velocities.
     
  7. Willys46

    Willys46 Well-Known Member

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    Without a Chronograph I would shoot at 2 know distances.

    100 yrd zero and 300yrds and work the velocity numbers backwards to get the velocity with a online ballistics caculator.

    the further you can shoot the better, if you can not get the drop to match then start looking at BC.
     
  8. Crop Damage

    Crop Damage Well-Known Member

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    Thank you all. I'm just trying to get an idea of the trajectory and power of this bullet, to compare to other loads. I'm going to form my own ballistics card on the range, just trying to get some ball park numbers. I was hoping to be close to 3100 with this load, and hope to increase that if it will still group well. Some more loading and a chronograph will help, and shooting on paper out to my 700 yard field edge. Just excited about the new rifle, and trying to plug in ballistics data on a rainy day.
     
  9. jwp475

    jwp475 Well-Known Member

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    A chronograph can be acquired for less than 100 bucks, it is wise investment
     
  10. Moman

    Moman Well-Known Member

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    I would try to pick up or borrow a chrono. What ballistic program are you using to do this?
     
  11. Crop Damage

    Crop Damage Well-Known Member

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    Right now I'm messing with the trial version of shoot 3.2. What programs do you all recommend?


    I didn't realize that a chronograph was that inexpensive, I'll get one. That would come in pretty handy.
     
  12. Moman

    Moman Well-Known Member

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    I use Exbal. It has a trajectory validation built into it that will adjust and give you what they consider a more precise velocity. If you dial in at say 600 yds and hit 4" low, you can enter this into the program and it will adjust and give you new readings for your drop chart. I have been using an old Pact chrono and it has done well for the last several years but is now starting to act up a bit. I think that I will replace it soon with a CED.
     
  13. jwp475

    jwp475 Well-Known Member

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    I use Exball on my desk top as well as on my hand held that I take into the field for real time info.

    With Exbal it locks in your sightin info (barometric pressure, temp, humidity) and undr field conditions corrects your info when you go from sea level as I do to the mountains to hunt

    [​IMG]


    and it works


    [​IMG]
     
  14. Crop Damage

    Crop Damage Well-Known Member

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    Exbal looks fantastic. I think that program and a CED pro chronograph would make great early Christmas presents for me. They would put me a long step ahead of my buddies. 2010 is looking really bad for the deer.