How to determine if a bullet will stabilize

[308sako]

I wish to shoot a Berger 80 grain flat base .243 diameter in my 21.5" 1 in 14 twist 6 XC, I think it will do 3300 ft/sec as 68's and 70's are doing 3600.

Is there a formula that can estimate a stability factor, and where might I find it?

Thanks

 

[CatShooter]

You need a 13" or faster twist.

 

[308sako]

LOL, how do I determine that, mathematically of course?

 

[CatShooter]

LOL, how do I determine that, mathematically of course?

You count the amount of dollars it takes to buy a program that does it for you )

The Greenhill formula that you will find on the internet was designed for blunt lead bullets and does not work accurately with modern bullets - especially the ones with a long aspect ratio.

 

[Big Mc]

Email Bryan @ Berger . He is the man. He will provide the mathematical cure you seem to be looking for..

 

[Steve Blair]

This recent Bulletin provides a link that will download Don Miller's Twist Formula in Excel spreadsheet form. The Miller formula is more accurate than the old Greenhill formula and correlates fairly closely with my results. [br]
http://bulletin.accurateshooter.com/2008/06/calculating-bullet-rpm-spin-rates-and-stability/

 

[dickn52]

http://bulletin.accurateshooter.com/2013/02/find-optimal-barrel-twist-rate-with-berger-stability-calculator/

Found this on that same page referenced above.

 

[308sako]

Gentlemen thank you for the responses and links, they have given me both knowledge and hope.

 

[Nomad47]

http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi