Does rifling twist direction matter, and does it matter in ballistic calculators? How does rifling direction affect the calculators?

[Dezelrig]

I see that some or most ballistic calculators have a check box for right or left hand twist. Hornady's 4DOF does not have this check box. Is Hornady making the assumption that everything is right hand twist?

I have a left hand Chanlynn barrel I'm attempting to dial in using 4DOF.

 

[clrblu22]

In short, Yes, it does have an effect on it. Frank talked about this just today (maybe yesterday) on his podcast "the everyday sniper". If you haven't subscribe yet, I definitely recommend it. Additionally, there are a few videos on Youtube that talk through the advantages of left hand twist barrels and how they negate a lot of the coriolis effect/spin drift.

 

[natdscott]

How far are you shooting?

 

[pell1203]

It does appear the Hornady 4DOF assumes everything is a right hand twist as there is no way to mark the input as left hand twist and there are no means to input a negative value into the calculator.

 

[Dezelrig]

With this particular rifle (.260 Rem) I’ll probably have to attempt shots out to 1400 at the local matches.

 

[Dezelrig]

In short, Yes, it does have an effect on it. Frank talked about this just today (maybe yesterday) on his podcast "the everyday sniper". If you haven't subscribe yet, I definitely recommend it. Additionally, there are a few videos on Youtube that talk through the advantages of left hand twist barrels and how they negate a lot of the coriolis effect/spin drift.

Okay. I’ll have to listen to what he says on the podcast.

Thanks!

 

[Lowlight]

Just turn off the Ground Effects and don't use the SD and the 4DOF will work

I reached out to Hornady about a few things missing in the app, an update is coming

 

[Snuby642]

Some calculators let you turn off spin drift and corialis.
With that off I get a 1 click difference at 600 yrds for a start unless we go subs then it shows up sooner?