Spin drift.

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Anyone have a good, easy and quick, chart or graph that charts out spin drift?

I'm shooting a 300 RUM at long range. Zeroed at 300 yards, finding the bullets impact 3 inches right at 600 yards.
They also impact left about 1.5 inches at 100 yards.

Corealis an impact also I'm sure.

I'm using Nosler 190 grain "long range" bullets, over H1000 pushing them out of a 30 inch Krieger at 3150 FPS at the muzzle.
 
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Zeroed at 300 yards, finding the bullets impact 3 inches right at 600 yards.
They also impact left about 1.5 inches at 100 yards.

I agree with others. Possibly canted scope.

OR

When viewing your scope and rifle from above as if shooting, your scope mounting has your scope twisted 1 MOA clockwise from the barrel axis which you’ve “corrected” to 1/2 MOA at 600 yards with your windage turret.

You need to check both.
 
At 10,000 meters it has an impact with artillery. Couple hundred yards with a rifle it is minimum.
 
Scopes off axis, includes the scopes internal adjustments also. Use a windage adjustable mount to zero. Scope adjustments should be centered.

Yes, spin drift is a thing.
 
Scope is level. I use a three level kit. Level the rifle (which is a Rem 700..the kits rifle level bridges the bolt rails, which is, by design, the place to do this on a 700). I use the second level in the kit on the scope itself, which is a Leupold 5HD. Once both those levels show.. level..I installed the third level on tye scope itself..for use on the bench and field to be sure the rifle is level before the shot.

Further more...I make sure the rifle is level front to back, and well as left or right twist...before I tightened anything down.

I think what going on..is indeed spin drift AND a touch of coreolis as well...as Im shooting almost dead south at my 600 yard range.

However...I do agree it still seems to be excessive, so, I'm going to recheck/remount everything with a different set of levels.
 
It’s Corealis effect, not Corvallis.

It’s Coriolis…

One of the elements of the 5-R rifling is a left hand spin to counter the right hand spin of spin-drift. (Northern Hemisphere).

5R rifling is not left hand twist, not by design at least. Some barrels ARE available in left hand twist, specifically ordered as such, but 5R is not inherently also left. I have something on the order of 25-30 5R barrels under my roof right now, not a single one is left hand twist.

Additionally, spin drift has absolutely NOTHING to do with hemisphere or rotation of the Earth, only the rotation of the bullet in the substrate. Coriolis doesn’t care which hemisphere you’re in either - If you’re shooting North, the world is moving to your right, if you’re shooting south, it’s moving left, shooting east it’s moving away from you, shooting west, it’s moving into you (Eötvös). How fast the Earth is moving under the bullet does vary by latitude, but doesn’t flip backwards by hemisphere.

Bullets aren’t toilets.
 
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Did you set your eye relief up? Easy mistake to do and if your looking through your scope, have any shading, your shot will be off.

From Leopold

A riflescope can be an intimidating piece of gear. A lot of people have it mounted at the local gun shop then never touch it again. But if you familiarize yourself with a couple of key techniques, adjusting your riflescope and even moving it between rifles can be quick and painless. As always, before you adjust anything, make sure your rifle is completely unloaded and that the environment is made safe before proceeding.

We recommend using a universal barrel leveling system. This is done before mounting the scope or installing the rings. Make sure the rifle is on a solid, secure surface and use a rear bag or rest to prop up the buttstock end of the rifle to get is as level as possible.

When adjusting your riflescope to work best for you, there are three main aspects to consider; getting the right eye relief, making sure the scope is level, and lastly, fine-tuning the scope's eyepiece focus. Let's take a closer look at these important factors.

EYE RELIEF
Knowing how to set up your scope for your body is critical to getting the best performance out of your optic. And since everyone’s built differently with different proportions, it’ll take some work to get it just right. One of the first things to consider is eye relief.

Eye relief is the point between the eyepiece lens and your eye where a full image can be observed. This point is different for every scope, so you’ll have to look up your model’s specs to know where it should sit on the rifle in relation to your eye. Also, note that eye relief slightly changes depending on what magnification you’re on. To get the best eye relief at any magnification, split the difference between the high and low eye relief numbers found on the specs sheet.


HOW TO SET YOUR EYE RELIEF
1. PLACE THE SCOPE in the rings and put the ring tops on, but not tightly. Make sure the scope can still move around. The scope on should be on its highest power which provides the smallest exit pupil size. This is critical because you want to make sure your alignment is perfect with the lowest exit pupil.

2. MOUNT THE RIFLE as if you were going to shoot – ideally, this is done on a table or stable platform. When looking through the scope, you want to be able to see a large image that fills the eyepiece. If you’re too close or too far away, you’ll get a lot of black around the image, which is called a vignette.

3. SHOULDER THE RIFLE WITH YOUR EYES CLOSED.Get in a comfortable shooting position that you’ll be able to duplicate every time you take aim. Once you feel comfortable, open your eyes to see where the eye relief is. You want to tailor the scope to your natural point of aim, not the other way around.

4. REPEAT THE PREVIOUS STEP until the scope is exactly where it needs to be. Remember, if done correctly, the image will completely fill the eyepiece – there shouldn’t be any black edges around your sight picture. Once your eye relief is set, make a mark with a pencil on the maintube where the rear ring meets it. This way, you'll know if the scope moves during the leveling process.
 
I'm shooting a 300 RUM at long range. Zeroed at 300 yards, finding the bullets impact 3 inches right at 600 yards.
They also impact left about 1.5 inches at 100 yards.

1.5” left strike at 100 would mean you have a minute and a half (at least) of Left built into your 300yrd zero - 4.5”at 300 …

3” right at 600 would mean a further 1/2moa of spin drift from 300-600…

See the problem here? If you had 1.5moa of “spin drift” at 300, why is it only gaining another 1/3 as much over the next 300 yards? Even with spin decay, that simply isn’t how spin drift works…

Coriolis and Eötvös are direction dependent influences, such if you’re shooting cardinal directions, you either have one or the other, but not both. At 100-300, you’re NOT getting 1.5moa of drift due to Spin Drift and/or Coriolis - that’s more than 10x the difference happening between 100-300. From 300-600, the 3” (1/2moa) you’re describing for that load would be an awful lot for combined South Shooting Coriolis + - 50% more than I’m seeing with my 300 wm and PRC load. Coriolis is only an issue if you’re shooting high North or South angles, and will have the opposite effect for either direction - AND - is damned sure not slinging you 1.5moa off course by 300yrds… total effect won’t even be 1.5moa at 1000 shooting due South with a right hand twist rifle… without, of course, an exacerbating wind…
 
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1.5” left strike at 100 would mean you have a minute and a half (at least) of Left built into your 300yrd zero - 4.5”at 300 …

3” right at 600 would mean a further 1/2moa of spin drift from 300-600…

See the problem here? If you had 1.5moa of “spin drift” at 300, why is it only gaining another 1/3 as much over the next 300 yards? Even with spin decay, that simply isn’t how spin drift works…

Coriolis and Eötvös are direction dependent influences, such if you’re shooting cardinal directions, you either have one or the other, but not both. At 100-300, you’re NOT getting 1.5” of drift due to Spin Drift and/or Coriolis - that’s more than 10x the difference happening between 100-300. From 300-600, the 3” you’re describing for that load would be an awful lot for combined South Shooting Coriolis + - 50% more than I’m seeing with my 300 wm and PRC load. Coriolis is only an issue if you’re shooting high North or South angles, and will have the opposite effect for either direction - AND - is damned sure not slinging you 1.5moa off course by 300yrds… total effect won’t even be 1.5moa at 1000 shooting due South with a right hand twist rifle… without, of course, an exacerbating wind…
Agree. Something doesn't add up. That why I created this thread.
I can zero the rifle at 100 yards, but then it hits right 1.5 inch or so at 300. Since it is a 300 RUM...100 yard zero is kinda.. well, pointless.

Also..something I've found with it...even before the rebarrel..it never did seem to settle its groups well at 100 yards. It just seemed to group better at 200 and 300 yards. That has never made much sense to me either. The Kriger groups much better at 100 compared to factory, but still not consistent as you think it would be.

300? It's dang deadly.
 
Have you tested your handloads against factory loads? Something to give you a base to go on.

Did you properly torque the action to the stock, scope rail & rings?
 
Since it is a 300 RUM...100 yard zero is kinda.. well, pointless.

That’s silliness of the highest order. Even top pro’s setting world records in ELR competition with cartridges which eat a 300 RUM for breakfast purposefully and intentionally zero at 100. Why? Because it ensures the greatest mechanical independence from environmentals.
 
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