Stability of 350gr Ranchdog boolit at slower speeds from 45-70

[ghh3rd]

I’ve been shooting 350 gr boolits from my Ranchdog mold in my 45-70 Guide Gun at about 1800 fps with very good accuracy. I’d like to experiment with lighter loads (slower) with the same boolit. Any idea how slow before they won’t stabilize out to about 100 yards?

Thanks

Randy

[Tom Myers]

I’ve been shooting 350 gr boolits from my Ranchdog mold in my 45-70 Guide Gun at about 1800 fps with very good accuracy. I’d like to experiment with lighter loads (slower) with the same boolit. Any idea how slow before they won’t stabilize out to about 100 yards?

Thanks

Randy

Randy,

The Precision Ballistics ~ 5 software application (http://www.tmtpages.com/New_Prec_Bal/bal.htm) uses the Bullet Stability Equations of Don Miller to calculate a bullet stability factor from bullet length, muzzle velocity, twist rate and atmospheric conditions.

A calculated stability factor of 2 is considered a safe minimum.

The Ranch Dog mold TLC460-350-RF has a calculated a sea level stability factor of 5.607 at a muzzle velocity of 1800 feet from a Marlin 1895 with a 1/20 twist. Well above the minimum factor.

At 500 yards, the velocity would decrease to approximately 1032 fps with a remaining calculated stability factor of 4.658. Still a very safe margin.

Hope this helps.

http://www.tmtpages.com/LinkSkyImages/forum_images/StabilityCalc/TLC460-350-RF/TLC460-350-RF-Bullet.PNG

http://www.tmtpages.com/LinkSkyImages/forum_images/StabilityCalc/TLC460-350-RF/TLC460-350-RF-Firearm.PNG

http://www.tmtpages.com/LinkSkyImages/forum_images/StabilityCalc/TLC460-350-RF/TLC460-350-RF-Stability.PNG

http://www.tmtpages.com/LinkSkyImages/forum_images/StabilityCalc/TLC460-350-RF/TLC460-350-RF-Trajectory.PNG

http://www.tmtpages.com/LinkSkyImages/forum_images/StabilityCalc/TLC460-350-RF/TLC460-350-RF-Stabilityat500.PNG

http://www.tmtpages.com/LinkSkyImages/forum_images/StabilityCalc/TLC460-350-RF/TLC460-350-RF-Sight-Settings.PNG

[ghh3rd]

Thanks for that information!