close
Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Rifles, Reloading, Optics, Equipment > Rifles, Bullets, Barrels & Ballistics

Rifles, Bullets, Barrels & Ballistics Applied Ballistics

Reply

sectional density question...soild vs jacketed

LinkBack Thread Tools Display Modes
  #1  
Unread 12-08-2010, 08:42 PM
Bronze Member
 
Join Date: Jun 2010
Location: santa maria,ca
Posts: 82
sectional density question...soild vs jacketed

This is comparing the same say for example .458 win mag 500gr barnes solid v.s. a standard 500gr jacketed soft point in same caliber,does the SD change?

I hope this makes sense. Im curious to know if it changes due to bullet material make. We are talking same caliber and weight.

thanks for any help or clearification.

Mike
Reply With Quote
  •   #2  
    Unread 12-08-2010, 09:00 PM
    Platinum Member
     
    Join Date: Oct 2007
    Location: Mountians of SW NC, near Asheville
    Posts: 1,595
    Re: sectional density question...soild vs jacketed

    SD is a simple math ratio of weight and diameter, no more.

    A solid copper or steel jacketed bullet of a given diameter and weight has the same SD as a thin jacketed hollow point with a soft lead core. Meaning SD tells us nothing useful.
    Reply With Quote

      #3  
    Unread 12-08-2010, 09:28 PM
    Platinum Member
     
    Join Date: Feb 2005
    Location: Nevada
    Posts: 2,782
    Re: sectional density question...soild vs jacketed

    Quote:
    Originally Posted by boomtube View Post
    SD is a simple math ratio of weight and diameter, no more.

    A solid copper or steel jacketed bullet of a given diameter and weight has the same SD as a thin jacketed hollow point with a soft lead core. Meaning SD tells us nothing useful.
    You may calculate the SD (Sectional Density) of any bullet by dividing the weight of the bullet (in pounds) by the square of its diameter.

    Example: a 30 caliber bullet of 180 gr.

    Weight in lbs = 180/7000 = 0.0025714 lbs.

    Square of its diameter = 0.308X0.308 = 0.9486

    SD = 0.0025714/0.9486 = 0.271

    As stated above, if the diameter and the weight are the same the SD is the same.

    SD is important because it has a significant effect on penetration. The higher the SD the better the bullet will penetrate assuming equal things like bullet design, materials, impact velocity etc.

    A 180 gr. 0.308 bullet will have better penetration than a 180 gr. 0.338 bullet. ( assuming many things being equal like design, impact velocity etc.)

    SD for the 180 gr. 0.338 would be: 0.225

    I hope that helps on getting a better understanding of SD.
    __________________
    -----------------------------

    -----------------------------
    HEBREWS 13:8
    Jesus Christ the same yesterday, and to day, and for ever.

    Our Lord Jesus said that as it was in the days of Noah and
    also as it was in the days of Lot so it shall be in the days...
    It's happening again!!! God sent to us His prophet, and His Word
    to this generation and we once more are rejecting it as was prophesied!!!

    ---> As promised, God Sent His Prophet to us!

    Last edited by Eaglet; 12-08-2010 at 09:34 PM.
    Reply With Quote
      #4  
    Unread 12-08-2010, 09:51 PM
    Bronze Member
     
    Join Date: Jun 2010
    Location: santa maria,ca
    Posts: 82
    Re: sectional density question...soild vs jacketed

    big help,thanks for the fast responses!
    Reply With Quote
      #5  
    Unread 12-09-2010, 09:26 AM
    Platinum Member
     
    Join Date: Feb 2005
    Location: USA
    Posts: 2,598
    Re: sectional density question...soild vs jacketed

    Quote:
    Originally Posted by Eaglet View Post


    SD is important because it has a significant effect on penetration. The higher the SD the better the bullet will penetrate assuming equal things like bullet design, materials, impact velocity etc.

    .


    The higher SD bullet does not always out penetrate a lower SD bullet of the same material and construction. Meplat and nose profile have a large bearing on penetration. Example solids made from the same material but with different nose shapes and profile. A 450 grain flat point mono metal solid in 458 caliber Will out penetrate a round nose 500 grain solid even at the same velocity. The flat point will shoulder stabilize and penetrate without the yaw and tumbling of the round nose.

    This thread is about conducting penetration test

    Terminal Bullet Performance - Topic Powered by Social Strata

    The thread is up to 112 pages at this point and in one test 2 bullet made from the same material and shape, but one at 435 grains and the other at 360 fired at basically the same velocity penetrated the same, not once but multiple times

    More to penetration than simply SD
    __________________
    range it,check the wind, dial in correction, aim and only one shot
    Reply With Quote
    Reply

    Bookmarks

    Thread Tools
    Display Modes


    Similar Threads for: sectional density question...soild vs jacketed
    Thread Thread Starter Forum Replies Last Post
    Air Density and Pattern Density Broken Brow Turkey Hunting 0 06-30-2011 09:21 PM
    Introduction and Load Density Question scoutm Reloading 4 06-25-2009 11:57 AM
    Sectional density, ballistic coefficient and wind drift dicktaylor Long Range Hunting & Shooting 4 05-28-2007 04:10 PM
    Sectional density ? ol mike The Basics, Starting Out 5 03-06-2007 10:01 PM
    sectional density's effect on bullet performance sscoyote Rifles, Bullets, Barrels & Ballistics 3 08-03-2003 01:07 AM


    All times are GMT -5. The time now is 12:10 AM.


    Powered by vBulletin ©2000 - 2016, Jelsoft Enterprises Ltd.
    Content Management Powered by vBadvanced CMPS
    All content ©2010-2015 Long Range Hunting, LLC