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

Estimating BC ....help!

LinkBack Thread Tools Display Modes
  #1  
Unread 02-24-2006, 10:43 AM
Gold Member
 
Join Date: Sep 2003
Location: Blighty
Posts: 637
Estimating BC ....help!

Got 50rds of 308 Geco 170gr target ammo for which I’m having trouble finding / estimating a ‘starting point’ BC to put me 'in the Parish' before I launch any downrange tomorrow.

They have good ogives but flat tips….....I’m confused!!
(yes, despite appearances,they are marketed as target bullets).

What would you estimate (I believe they are flat base)??:

Geco in the middle, 165gameking on left (0.404), 165NBT on right (0.475)……the ogives appear similar….just the tips seem different:



The ogive is looks too good to class them with the Sierra Prohunter 170 FN (BC: 0.204).

Some more views of the Geco 170gr tip:






Anyone got anything more edumacated than (0404 + 0.475 + 0.204)/3 = 0.361 ?


Thanks!
Reply With Quote
  •   #2  
    Unread 02-24-2006, 11:17 AM
    POP POP is offline
    Platinum Member
     
    Join Date: Jul 2001
    Location: CHEYENNE, WY
    Posts: 1,446
    Re: Estimating BC ....help!

    .350?
    __________________
    "Weatherby was too long so I nicknamed it "Bee""
    Reply With Quote

      #3  
    Unread 02-24-2006, 11:35 AM
    POP POP is offline
    Platinum Member
     
    Join Date: Jul 2001
    Location: CHEYENNE, WY
    Posts: 1,446
    Re: Estimating BC ....help!

    kINDA LIKE THESE:

    Awesone performance. Too bad Low BC.
    [img]/ubbthreads/images/graemlins/crazy.gif[/img]

    http://www.northforkbullets.com/308-165.htm
    __________________
    "Weatherby was too long so I nicknamed it "Bee""
    Reply With Quote
      #4  
    Unread 02-24-2006, 12:50 PM
    Platinum Member
     
    Join Date: Jun 2001
    Location: Potomac River
    Posts: 5,071
    Re: Estimating BC ....help!

    look at the Speer 30 cal Mag Tips

    170 gr has a BC of 0.304
    180 gr has a BC 0f 0.352
    __________________
    The Smokin Fur Rifle Club
    Reply With Quote
      #5  
    Unread 02-24-2006, 01:24 PM
    Gold Member
     
    Join Date: Sep 2003
    Location: Blighty
    Posts: 637
    Re: Estimating BC ....help!

    Thanks.

    That's brought the average down to about 0.34.

    -I'll give it a go at that!
    Reply With Quote
      #6  
    Unread 02-24-2006, 04:13 PM
    Gold Member
     
    Join Date: Mar 2004
    Location: Spokane, WA
    Posts: 521
    Re: Estimating BC ....help!

    BD, Unfortunately, flat nosed, flat based bullets have a much lower BC. Hopefully, they shoot great to offset their range limitations. Good luck.
    Reply With Quote
    Reply

    Bookmarks

    Thread Tools
    Display Modes


    Similar Threads for: Estimating BC ....help!
    Thread Thread Starter Forum Replies Last Post
    Reticle Range Estimating.... Buttermilk Specialty Handgun Hunting 2 11-03-2008 07:54 AM
    Estimating Range with a GPS?? Dennis_in_VA Rifles, Bullets, Barrels & Ballistics 11 12-07-2007 11:43 AM


    All times are GMT -5. The time now is 02:17 AM.


    Powered by vBulletin ©2000 - 2017, Jelsoft Enterprises Ltd.
    Content Management Powered by vBadvanced CMPS
    All content ©2010-2015 Long Range Hunting, LLC