Rifle shoots to the right? Need suggestions please?

[New shooter]

I recently purchased a Rem 700 5R Mil spec in 308. It shoots great out to 400 yards. After 400 it starts to roll to the right regardless of wind. At 600 it is about 5" and at 900 it is about 12".
I assume this is due to spin drift?
If anyone has experience with this, please let me know what else I should check of if this is normal?
Thank you!
Mike

 

[brfun]

Mike
Without knowing all the variables like twist, velocity, bullet, bc, atmospheric conditions and so on these might be close at best. Spin drift assuming a 0 wind contrition witch rarely happens 400= about 1” 600 about 3” 900 about 7” so it doesn’t look like you to far off from that. Even a 1mph 9:00 full value wind added to the spin drift could easily give somewhere around 15” to the right at 900.
Brian

 

[k80skeet]

This is completly normal for a right hand twist barrel. Mine are normally 3" to the right at 600 yards and 1 1/2" at 400yards. At 400 I go 1 click too the left and 2 clicks to the left at 500 & 600 as long as you have 1/4" clicks. If you have 1/8" ckicks you will have to double the chicks.

 

[New shooter]

Thank you for the feedback. I was not sure if this was typical or something could be wrogn with my hardware.
The twist rate is 11 1/4" 5R rifleing with 24" barrell. I am shooting 175 gr. SMK at 2630 fps.
This past weekend was my first time to shoot this year after shoulder surgery and past 700 yards which was a not such a good comination. I was able to keep my 900 yard group at 3" just right and low of bull.
Any other suggestions are appreciated and I will make a note for right hand DOPE on longer range.
Thank you again,
Mike

 

[mikecr]

I may be off here, but it seems like you could turn your scope in the rings a touch clockwise to counter.

 

[Erik Cortina]

Rifle shoots to the right? Need suggestions please?

My suggestion is to click your scope to the left! ;D

Joking aside, it's more than likely due to spin drift, it's normal!

-Erik

 

[rfair]

I agree with mike, I'll bet the scope is canted!

 

[GerryM]

K80 is correct. on the right hand twist.
The natural Exit is right . { flight path is right.]

 

[rain164845]

I would bet your scope is canted.
Joe

 

[New shooter]

Thank you all for the suggestions and you were correct on the canted scope. I spoke to Terry Cross today and he suggested using a plumb line and running the scope to distance. It became evident that the bubble in my scope is not accurate and cross hair moved to the left side of the string as I got to the 500 yard and above DOPE. Problem solved and look forward to more shooting.
Thank you all for the suggestions.
Mike

 

[Erik Cortina]

I bet you will still have spin drift though!

Glad you found the problem! Happy shooting!

-Erik

 

[k80skeet]

Me Too!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Never seen one that didn't

 

[white121]

I just wanted to check about this spin drift? Is this because of the 308 cartarige slowing down to subsonic that creates this drift? I have a 6.5-270 zeroed at 200 and with no wind at 600 yards I have never had to account for spin drift if their is no wind just use my elevation and Im on! Not trying to be a smart a#% just trying to learn as I am pretty much a rookie but With me 6.5-270, 243 ackley ect. never seen this spin drift you speak of.

Shaun White

 

[PHINPAD]

Shaun,

Bryan Litz explains it much better than I ever could, if you were ever tempted to buy his book then get it now, not only to answer this question but as an eye opener on other topics too.

 

[ThunderDownUnder]

A lot of people are curious about barrel twist rates and bullet stability and for good reason. Nobody wants to waste their money on a barrel that wont stabilise the bullet they have chosen for use in competition (or hunting).

Everyone now knows about Bryan Litz's book "Applied Ballistics For Long Range Shooting" and how by using the software included with the book you can obtain the Sg (stability factor) for your bullet. Bryan recommends a Sg of around 1.4 for optimal stability but a bullet with an Sg of 1.0 or more is regarded as stable.

The other interesting aspect of gyroscopic stability is gyroscopic drift (spin drift). A 308W may drift around 8 inches to the right at 1000 yards just thru this effect. If the rifle twist is to the right then bullets will drift to the right and vice versa.

If you have not got Bryan's book yet, then I have made available for download an Excel spreadsheet that does both of these things. The only inputs you need are your rifle and bullet data along with the bullet time of flight which you get from a ballistics program.

The spreadsheet calculator file is here: http://www.safclass.com/downloads.html

A free ballistics program from Berger Bullets can be downloaded here: http://www.bergerbullets.com/Ballistics%20Program/index.html

Its now pretty easy to check your bullet stability and gyro drift thanks largely to Bryan Litz making this information so easy to understand and use!

Ian

 

[white121]

Thunder down under

Thank you for posting the links and the reason I have not notice this affect is its only 1inch at 500 and a little more at 600 with my rifle and I have not shot passed 600 before and I guess there has not been enough spin drift affecting me to really notice!

Shaun White