Originally Posted by benchracer
I ran some stability calculations using the Miller Stability formula on JBM Ballistics to see what I could find out. These calculations were run @ standard temperature and pressure, so they are not altitude corrected.
To my surprise, the Barnes 50g TSX does not stabilize in a 14 twist. The 45g TSX shows marginal stability, but does stabilize.
Another mono-metal option would be the Cutting Edge 40g Raptor. CE says it stabilizes in a 14 twist and the Miller formula agrees, though the stability factor again shows marginal stability.
The 60g Nosler partition does not stabilize.
Sierra says their 60g Varminter will stabilize, but couldn't verify that by calculation because I couldn't find a listing for bullet length. I wasn't able to do any calculations for the 63g Varminter for the same reason.
Couldn't find length info for the Winchester 64g Powerpoint, so no calculation for that one either.
Berger says their 55g Target bullet works in a 14 twist. Miller formula says no.
I didn't realize that there is a list of some bullet lengths compiled on the JBM website. Using what I could find on that list, I plugged some numbers into the calculator on the Berger website. All calculations were run a 59*F and 0 Ft. Altitude. If you plug in expected temperature and altitude for where you hunt, you will obviously get more accurate numbers for your conditions.
Here is some info to muddy the waters a bit on the subject of what bullets will stabilize from a 14 twist 22-250:
Sierra 55g Game King (length .724) @ 3600 SG=1.1 (marginally stable)
Sierra 60g HP Varminter (length .776) @ 3600 SG=.99 (unstable)
Sierra 63g Varminter (length .755) @ 3500 SG=1.11 (marginally stable)
Hornady 55g Spire Point (length .715) @ 3600 SG=1.14 (marginally stable)
Hornady 60g Spire Point (length .700) @ 3600 SG=1.33 (marginally stable)
Hornady 60g Spire Point (length .750) @ 3600 SG=1.09 (marginally stable)
Nosler 60g Partition (length .790) @ 3600 SG=.94 (unstable)
Barnes 45g TSX FB (length .698) @ 3900 SG=1.03 (marginally stable)
Barnes 50g TSX FB (length .736) @ 3700 SG=.97 (unstable)
A few things are worth noting here. First, the JBM website says the Hornady 60g Spire Point is shorter in length than the 55g bullet of the same design. I think that length measurement is suspect. I did some digging and found where someone had measured their 60g Spire Point at .750. I plugged in and ran both sets of numbers for that bullet.
Sierra states that the 60g HP Varminter is designed to work in 14 twist 22-250's and Swifts and that it does just that. The calculator says no, but just barely. I believe there is likely some wiggle room here.
I also ran across a post from someone who had called the Barnes tech line to ask about the 45g and 50g TSX FB bullets in a 14 twist. According to that individual, Barnes technical personnel stated that the 45g and 50g TSX FB bullets were specifically designed for 14 twist barrels in 22-250 and .220 Swift and that extensive testing had shown that both bullets will reliably stabilize in a 14 twist. Barnes online load data appears to back that up. Note also that the velocities I plugged in to the Berger calculator for these two bullets are notably conservative compared to the Barnes data.
One final note on the Barnes bullets is that I got my length information from the MidwayUSA website. That was the only place I could find it. Sometimes their posted information is accurate. Sometimes it's not. I have been bitten before when using data taken from Midway.