Spin Drift

[baconeater20]

I have read here and there on spin drift. My comfort range is getting longer and longer. Pretty comfortable at 500 yards being that is the furtherest I can shoot on my property. Got a friend who is letting me set up on his land that is perfect for about 920 yards. SO back to the spin drift. I made a little spred sheet that will calculate for you. Just plug in the info of your SG and Time of flight and it will give it to you. If you are intested in it I can email you the spread sheet. Just thought I would offer.

MKG

 

[Rich Coyle]

How much info do you need to determine spin drift?

 

[baconeater20]

All you need is the SG and the TOF of the bullet at the distance you are shooting. Plug those numbers in and you have the drift in inches.
MKG

 

[Hatrick]

Does rate of twist make a difference?

 

[baconeater20]

Now I am no pro but the twist rate and fps has alot to do with the SG of the bullet. On Bergers Website they have a SG calculator.

MKG

 

[baconeater20]

Maybe someone with more knowledge will chime in.

 

[Elkeater]

I'm not really sure how to calculate it. I'm pretty sure that speed and twist rate play into spin drift and I know that running the shooter app on my phone accounts for spin drift. Guess I'm not much help on this one.

 

[barefooter56]

I have read here and there on spin drift. My comfort range is getting longer and longer. Pretty comfortable at 500 yards being that is the furtherest I can shoot on my property. Got a friend who is letting me set up on his land that is perfect for about 920 yards. SO back to the spin drift. I made a little spred sheet that will calculate for you. Just plug in the info of your SG and Time of flight and it will give it to you. If you are intested in it I can email you the spread sheet. Just thought I would offer.

MKG

THIS:
http://www.appliedballisticsllc.com/Articles/ABDOC108_GyroscopicAndCoriolis.pdf

 

[baconeater20]

THIS:
http://www.appliedballisticsllc.com/Articles/ABDOC108_GyroscopicAndCoriolis.pdf

Thank you sir.

 

[jjmp]

does it compensate for a right hand or left hand twist?

 

[baconeater20]

Like I said I am rather new to this but from what I have read if its a right hand twist then the spin drift would be to the right and to the left for left hand twist.

MKG

 

[jjmp]

10-4 thks you know more then me!!!! i'm trying and reading all I can.

 

[mpk1996]

most ballistics apps will calc spin drift. and if you have your parameters set right (R or L twist) it will calc correctly. basically its like how a golf ball curves through the air. For most shooting you will see .1 mil around 500-800 and around .2 mil from 900-1100 of spin drift to the right in a right twist barrel (which most are). a good way to see this is put in 0 wind in your ballistics app and you will see at distance that you will need to add "windage" this is spin drift