Thread: How does barrel twist affect ballistics calculations?

Hey strider the short answer to your question is that twist rate is unlikely to be the reason for the differences.

I would suspect it’s either environmentals or the fact that Hornady 4Dof apparently use Doppler readings to map the projectiles entire flight rather than just assign an average bc.

The sigs are great in my experience but will only give you a ballistic solution out to 800yards. Sig recognise there are accuracy limitations to its ballistic calculations past this point.

As you get past about 500m with your 139gn projectile it’s factoring in the environmentals and your altitude that will give you accurate dope.

The sigs don’t factor in any of this unless you pair a kestrel.

The Hornady app will factor it in but only if you manually set the correct data or have cell reception to update the weather in the app.

Hopefully some of that made sense.

I probably should have asked, how far do you need to shoot?