Denser core material?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by MAX, Aug 22, 2003.

  1. MAX

    MAX Well-Known Member

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    A discussion in this site awhile back pitted disciples of different ballistic persuasion, one using homogeneous copper alloy bullets, the other discussing bullets with tungsten cores, the idea as I understood it being a denser core having superior ballistic properties.

    So, denser than what? Tungsten(atomic wt. approx. 183) is denser than copper(atomic wt. 63), but not as dense as lead(Atomic wt. approx 207). The only material I see denser than lead that may be useful is bismuth(atomic wt. almost 209) due to availability and characteristics.

    I am not trying to start a riot with this, but if I missed something, please clue me in. [​IMG] The formula for BC involves form, diameter, and weight; the limitation on long forms being largely the required twist to stabilize it. Wherein lies the ballistic advantage of lighter core materials than lead? BC is proportional to SD for a given form after all.
     

  2. Richard338

    Richard338 Well-Known Member

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    You need to look up the DENSITY of these materials, not the atomic number. Tungsten is much denser than lead.
     

  3. Brent

    Brent Well-Known Member

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    Max,

    Interesting. Are the numbers there correct, I thought tungsten to be higher than lead? Maybe it's the "alloy" that does it, but that don't make sense either, tungsten is suppose to be the big heavy weight in the alloy. The article in the book I have says that tungsten is heavier than lead FWIW.

    Here's one for ya; If a 30 caliber 268gr bullet is still going 1809 fps at 1000 yards when it left the muzzle at 2778 fps, what's the BC, and how would that BC fit with most conventional lead core bullets? The bullet was fired from a 30 FBI and velocity was tested at 1000 yards, it's not from a table.

    I've got a good article on the powdered tungsten core bullets if you're interested in reading it?

    Interesting stuff.
     
  4. MAX

    MAX Well-Known Member

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    Thanks for the nudge. The numbers I quoted above are atomic WEIGHTS not atomic(periodic) numbers and I ASSUMED that atomic weights denoted density. That is incorrect. Suffice it to say, lead is DENSER than bismuth, tungsten more so than lead etc, etc. I stand corrected.

    Brent, I'd like to see the article if possible. Apparently the data for the .30 FBI is insufficient for the JBM program, or perhaps my mind. Still diddling with that one.

    Thanks to both of you.
     
  5. Brent

    Brent Well-Known Member

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    Max,

    Emailing to you now. Email's good right
     
  6. MAX

    MAX Well-Known Member

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    Yes it is, thanks. After reviewing www.webelements.com I find 'W' to be approximately 70% denser than 'Pb'. If that's right...Oh dear....do they make powders slow enought to work with that?
    Noticed quite a few others with greatly higher densities as well. Surprised me. Guess I haven't passed the too old to learn barrier yet.
     
  7. Mysticplayer

    Mysticplayer Writers Guild

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    I will throw my two cents into this ring.

    For me and LR target shooting, I want the bullet with the highest BC number with the lightest weight in a given calibre. This means that I would lean towards a solid copper or similar type bullet. This material would also have to be very durable so that it could withstand the high RPM's when travelling at least 2800fps, preferably 3000fps.

    If I was trying to "kill" something, then I would want high BC but allow very high bullet weight and extremely tough jacket material. This is best shown by the nasty stuff that comes out the front of an A-10's cannon.

    The use of depleted uranium is to have a very dense and heavy core to aid in penetration of hardened targets.

    So the question that Max poses has two correct answers depending on the bullet's use.

    The perfect 1000m BR bullet would be a 6mm bullet weighing 85 to 95gr that was over 1.5" with a BC exceeding 0.85. The material would withstand being spun in a 1in6 twist at 3000fps. Now that would be technology...

    For LR hunting out to 1500yds, it would be a 6.5mm bullet over 2" long weighing 120 to 140gr with a BC also exceeding 0.8. Since we are dreaming, why not BC at 1.0 with a SD over .4. Twist rate would be very fast for sure.

    That way recoil would be very tolerable, throat life excellent, bullet almost not slow down, SD amazing for excellent ongame performance. This dreaming could extend to all calibres.

    Jerry
     
  8. CAM

    CAM Well-Known Member

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    Brent

    Load from-a-disk said about .86 BC for that bullet.

    Caution that is just the best guess I have, I pluged in 2778 muzzle with a .30 cal bullet 1.5" long and keep changing the BC untill the 1K Velocity was at 1808 FPS.

    Buy the way I never thanked you for the 30-378 data you e-mailed me THANKS CAM [​IMG]
     
  9. Brent

    Brent Well-Known Member

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    Cam,

    In theory, they said it's .91 BC but, I'd take an .86 BC and somehow try to find a way to make it work out. [​IMG]

    30/378 Wby data, no sweat, anytime. Want a copy of the PRL TC article I have here?

    Jerry,

    Why light bullets for target work? Recoil?
     
  10. texas

    texas Well-Known Member

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    Brent, are you back now? I think everyone should read that article.

    I printed a copy and I saved it in my e-mail so I'll always have it. [​IMG] [​IMG]
     
  11. Brent

    Brent Well-Known Member

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    Texas,

    How ya been?

    I did email you back on the 15th when I got back. Did it get lost? Wondered where ya been.

    The PRL article "is" a good one.

    Here's another nice bunch of info you all here might find usefull at some point, she sure knows her $hit!!

    aeroballisticsonline.com
     
  12. MAX

    MAX Well-Known Member

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    Brent, thanks for the article email. Really appreciate that. The fog begins to rise... [​IMG]

    Jerry, thanks to you for your comments. Question for you, not intended to create chaos: Why do you like the 'long light' for target work? The philosophy seems to favor form over mass in search of BC/lower Cd. Does that not compound yaw of repose issues? BTW, to my surprise, according the web site linked above, tungsten is denser than uranium by a minor amount. I gather it is more problematic to work with due to characteristics however.

    Thanks to all.
     
  13. Brent

    Brent Well-Known Member

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    Max,

    You want to make your own TC bullets?

    corbins.com/powder.htm

    Here's the equipment you want. I'm going to contact them to see who's geared up and making them right now, and selling them. Powell River Laboratories is now Brown Dog Ent. from what I've found out, can't find anything on the net for them tho. I do have a ph# for them in California tho. It seems PRL was several thousand dollars behind on rent for their building for a few years, and finally lost it last year, about all I found on them.

    Corbin has some great info in their site concerning bullet design, shape, stability and accuracy vs. high BC forms...

    corbins.com/bullets.htm#uld

    corbins.com/benchrst.htm

    corbins.com/topics.htm
     
  14. texas

    texas Well-Known Member

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    Yeah I'm still here [​IMG].

    If you want to know who else has them check out custom they do them.