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Thread: cast boolit coefficient?

  1. #1
    Boolit Man Knightflyer's Avatar
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    cast boolit coefficient?

    I was fiddling around with the Hornady ballistics calculator, which got me to wondering what the coefficient was on some cast boolits I bought, and some others I was considering. The first is from Falcon bullets, a 30 cal, 165gr, RNFP that is either regular lubed or poly coating. Comparing it to similar things, I'm guessing it to be around .28. The other one is the Badman bullets, a 135gr which also has either plain or a poly coated version.

    Knightflyer in CO

  2. #2
    Boolit Grand Master tazman's Avatar
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    Use the search engine and search for cast boolit coefficient. You will get several threads covering this.

  3. #3
    Boolit Master
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    The 165 grainer will probably be right around .2, give or take a little.

    The 135 grainer, maybe .18 or so.
    Last edited by outdoorfan; 03-06-2018 at 10:04 PM.

  4. #4
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    Go to this link on this site and see what similar boolit may give you for a Coefficient:

    http://castboolits.gunloads.com/show...efficent-Table
    Mustang

    "In the beginning... the patriot is a scarce man, and brave and hated and scorned. When his cause succeeds, the timid join him, for then it costs nothing to be a patriot." - Mark Twain.

  5. #5
    Boolit Master
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    Btw, my "guesses" are based upon actual tests that I've done with similar designs. So, I'm not basing my estimation off of a chart, but on actual testing.

  6. #6
    Boolit Grand Master popper's Avatar
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    NOE has BC if you find a similar boolit.
    Whatever!

  7. #7
    Boolit Buddy
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    Lee also lists the BC of their cast stuff.
    Again, find something similar and go from there.
    Benny

  8. #8
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    I've found in actually measuring the BCs via time of flight (M43 Oehler with screens at muzzle and in front of 100 yard target) that most cast bullets have BCs slightly lower than the "calculated" BC we find in mentioned sources. For example a 164 gr cast with a calculated BC of .280 - .290 will actually have a measured BC of .240 to .250 at velocities of 1700 to 2200 fps.
    Larry Gibson

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    ― Nikola Tesla

  9. #9
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    Quote Originally Posted by Larry Gibson View Post
    I've found in actually measuring the BCs via time of flight (M43 Oehler with screens at muzzle and in front of 100 yard target) that most cast bullets have BCs slightly lower than the "calculated" BC we find in mentioned sources. For example a 164 gr cast with a calculated BC of .280 - .290 will actually have a measured BC of .240 to .250 at velocities of 1700 to 2200 fps.
    Larry,

    Have you ever checked jacketed bullets? Do they measure close to "spec" or do you see the same degree of deviation?

    Sorry for the thread drift!
    Don Verna

    NRA Endowment Member

  10. #10
    Boolit Man Knightflyer's Avatar
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    Quote Originally Posted by tazman View Post
    Use the search engine and search for cast boolit coefficient. You will get several threads covering this.
    Thank you! I had tried a search, but I spelled it wrong...

  11. #11
    Boolit Man Knightflyer's Avatar
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    Quote Originally Posted by outdoorfan View Post
    Btw, my "guesses" are based upon actual tests that I've done with similar designs. So, I'm not basing my estimation off of a chart, but on actual testing.
    Great info ODF! I'm afraid I might like, just a teeny-tiny-bit, to geek out on this stuff.

    I had originally thought about casting my own boolits, but honestly, since I can get the Badman plain cast boolits for 8.2 cents if I order a thousand, I'm thinking I'll let them do that part lol. Hard to beat the price once I figured in my time & trouble. Maybe when I get closer to retirement and the kids are really all out of the house. My wife is already squawking about the time I spend with my new toy. I got a Mossberg 464 30-30 at a gun show last month. I really do try not to fondle it in front of her...

    Once I've tested the load I'm working on and am sure my reloads work okay, I want to take her to the range. She has arthritis and while she's gone shooting the pistols with me, it's hard on her. But if I can get her to try these Oliver-sneeze* loads, I think she might learn to like my new mistress.

    For the curious, I loaded a 165 grain Falcon poly-coated boolit over ~5 gr of Titegroup last night. I hope to go try these this coming Sunday. The range I use is kinda far away (1 hr) so the only day I can really go is on Sundays.

    * Oliver is our huge orange cat. He's very lazy, and Very dumb. We joke that he plays cards with his 'friends' - the mice. Our other two cats leave the mice alone because they don't want to make Oliver cry by eating his Friends.

    -Knightflyer
    Last edited by Knightflyer; 03-07-2018 at 12:31 PM.

  12. #12
    Boolit Man Knightflyer's Avatar
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    Quote Originally Posted by dverna View Post
    Larry,

    Have you ever checked jacketed bullets? Do they measure close to "spec" or do you see the same degree of deviation?

    Sorry for the thread drift!
    Naw, let it drift! You've got my attention now! I'm guessing the jacketed bullets will be closer due to not having lube channels, but that's just an educated guess.
    -KF

  13. #13
    Boolit Grand Master


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    Quote Originally Posted by dverna View Post
    Larry,

    Have you ever checked jacketed bullets? Do they measure close to "spec" or do you see the same degree of deviation?

    Sorry for the thread drift!
    I will be more than glad to answer that question on goodsteelforum.com since I have measured the BCs of numerous jacketed bullets of various caliber and make also. Since the answer involves topics that bring out negative responses from several who simply wish to disagree with anything I say I'll not answer on this forum.
    Larry Gibson

    “Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
    ― Nikola Tesla

  14. #14
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    I will answer why they measure lower than calculated on the artful bullet forum if anyone is interested.

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    Boolit Master Cowboy_Dan's Avatar
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    Larry and Run, I am interested in both. Could you post links if either of you do post on the subject? I just checked both forums and was unable to find either. Thanks!
    "It is wrong always, everywhere, and for everyone to believe anything on insufficient evidence."
    -W. K. Clifford "The Ethics of Belief"

    "They hate you if you're clever, and they despise a fool."
    -John Lennon "A Working Class Hero"

  16. #16
    Boolit Man Knightflyer's Avatar
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    Hah! I figured out who made the 135 gr bullet mold! It's Magma custom engineering company! Here's their mold catalog. If you look at the 30 cal section, that's the identical bullet. I shot an email to their sales to see what they can tell me about that bullet and a 165 gr that is also definitely their make.

    Tracking this is more fun than playing Where's Waldo with kids! Well, maybe not quite, but my kids are too old to fuss with Waldo anymore. I need my oldest daughter and her 'significant other' to get hitched and have some grand-kids. I mean, they've been together for six years...

    (tune of Matchmaker from Fiddler on the Roof)
    "Mold maker, mold maker, make me a mold! Pour in the lead, bullets to hold! Mold maker mold maker make me a mold! Oh make me the perfect mold!"
    -Sincere apologies to Jerry Bock
    Last edited by Knightflyer; 04-03-2018 at 03:03 PM.
    Knightflyer - Pesky newbie with a 30-30 & a zillion questions
    "And what I want to say is this, that I'm the King's man; and if this Parliament of Owls is any sort of plot against the King, I'm having nothing to do with it." - C.S. Lewis, The Silver Chair
    Shalom y'all!

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