Long Range Hunting Online Magazine


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


Reply

Actual B.C. VS Claimed

 
LinkBack Thread Tools Display Modes
  #8  
Old 01-30-2008, 10:06 PM
Gold Member
 
Join Date: Jun 2004
Location: Worland, Wyoming
Posts: 568
My reason for starting this thread is aimed at predicting terminal performance in long range hunting situations. If a bullet is advertised as having a high bc but really doesn't, then the choice that is made might not be the best for long range clean kills. Like many people, I might get caught up in how well bullets do on paper based on velocity and bc. Lower bc's loose velocity faster and with the velocity loss comes lower retained enery. I like to pick loads that have maximum retained energy and accuracy for best long range terminal performance.
__________________
Remington model 700 300 RUM LH 26" rem ss/blued receiver lam stock 215 Berger @3025/180 NAB @3300
Remington model 700 338 RUM LH 27" Broughton 5C 225NAB@3300 /300gr Berger@2830
Savage LH 22-250
Reply With Quote
  #9  
Old 01-31-2008, 01:24 AM
Gold Member
 
Join Date: Jan 2007
Location: South Dakota
Posts: 753
Quote:
Originally Posted by D.Camilleri View Post
My reason for starting this thread is aimed at predicting terminal performance in long range hunting situations. If a bullet is advertised as having a high bc but really doesn't, then the choice that is made might not be the best for long range clean kills. Like many people, I might get caught up in how well bullets do on paper based on velocity and bc. Lower bc's loose velocity faster and with the velocity loss comes lower retained enery. I like to pick loads that have maximum retained energy and accuracy for best long range terminal performance.

In that case, go buy some big ol hams or roasts and blast em from the distances you want to shoot at.

Mmmmmmmm, smell the carnage. . .
__________________
Chad Dixon
Reply With Quote
  #10  
Old 01-31-2008, 11:37 PM
Gold Member
 
Join Date: Jun 2004
Location: Worland, Wyoming
Posts: 568
I was thinking more on the lines of some soon to be delisted elk eating wolves!
__________________
Remington model 700 300 RUM LH 26" rem ss/blued receiver lam stock 215 Berger @3025/180 NAB @3300
Remington model 700 338 RUM LH 27" Broughton 5C 225NAB@3300 /300gr Berger@2830
Savage LH 22-250
Reply With Quote
  #11  
Old 02-02-2008, 06:20 PM
Bronze Member
 
Join Date: Jul 2005
Posts: 63
The entire concept of BC is based on mathematical "models" that are themselves based on real-world observations...in other words...a long time ago somebody threw a bunch of various shaped rocks downrange and took notes on what happened to them.

All of the current ballistic computers are based on those notes, and the degree of exactitude expressed therein should not be taken literally, as it is not an exact science. At best, a model represents a scientific attempt towards a "best guess".

The testing performed to arive at a BC number is very rudimentary, as the equipment necessary to measure BC in a more finite way is generally well beyond the resources of the small arms community. Even if that advanced analysis were to be undertaken, the figures still get plugged back into some mathematical model or another...and then we are right back to making guesses.

Now, some of these guesses can turn out to be pretty close, and often are, which is lucky for us, the shooter, because usually all we are really interested in is how many elevation/windage clicks are necessary to get on target... and that is fortunate.

The best way to figure all that out is to do some range testing and try to find out where the bullets are landing most of the time...just like those rock throwers of long ago. The range method really works, and once you plug some real world drop data back into a ballistic computer, you should be good to go for other environments as well, but only for that particular rifle...that load...and that bullet.

That is because factors related to the individual rifle, like barrel harmonics, site height, and a few others, will also effect drop data, and the resultant BC number.

So in the process of doing your own real-world ballistic testing you can use reverse logic to come up with a BC number that gives drop performance that is close to what the programs predict for the bullet you are using.

If the program you use is pretty close to your real world results, then that is the best BC number to use, regardless of what the manufacturers have published...a bit more testing will determine that. That does not necessarily mean that the BC figure you come up with is will be the correct one for your buddy using a different rifle rig.

Basically, the manufacturers BC rating is really only there for comparison purposes, and just like the EPA mileage ratings manufacturers assign to cars...your mileage may vary!

TC
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Actual B.C. VS Claimed
Thread Thread Starter Forum Replies Last Post
How many actual snipers out their Rifles, Bullets, Barrels and Ballistics 24 09-30-2009 01:27 AM
Actual B.C. hank shaper Reloading 11 02-14-2007 05:28 PM
actual MV drpbroun5 Rifles, Bullets, Barrels and Ballistics 3 12-15-2006 03:45 PM
How can I determine my actual BC? sewwhat89 Rifles, Bullets, Barrels and Ballistics 6 09-15-2005 11:32 AM
Actual BC of Berger bullets??? trader388 Rifles, Bullets, Barrels and Ballistics 4 01-21-2005 09:16 PM

Current Poll
I currently have hunting preference points in the following states

All times are GMT -5. The time now is 03:07 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC