Do Not Mount Your Scope Level

Your correct, if he only ever shots due north that might help, but twice as far off shoting due south.
That is not true. In the Northern hemisphere, the Coriolis effect will cause the bullet to always hit right of the target whether aiming north or south. Aiming due north the bullet will strike the same distance right as aiming due south hits right. In between due north or due south the correction is less right, but still always right. Unless you are shooting south of the equator, then the Coriolis effect is always left.
 
Oh. No kidding I thought it was hitting right shooting south and hitting left shooting north.
So it shoots right whether shooting north or south (both ways)? Does it still shoot right if you're shooting East or west? I thought shooting East/west was just a matter of hitting low vs hitting higher
 
I was that poster that sights in slightly left. Don't cant your scope to account for it. That will effect your vertical adjustment and really can't be done precisely. I would not recommend that in the slightest aspect. Just mount it level and center it up at 700 yards, or sight in a little left. Much more simple. Of course the further out you shoot, you really need to take it into account. But within 800 yards, just 1/2 MOA Left at 100 yards will have you covered.
Yes, I agree about canting also changing the elevation ARC. My implied question is: is the elevation ARC correction caused by a canted scope greater than the spin drift correction created by canting? Your 1/2 MOA bullseye error is also a compromise and not accurate at all distances. So, which scope error compromise (canting or 1/2 MOA) causes the smallest error in windage and elevation?
 
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Oh. No kidding I thought it was hitting right shooting south and hitting left shooting north.
So it shoots right whether shooting north or south (both ways)? Does it still shoot right if you're shooting East or west? I thought shooting East/west was just a matter of hitting low vs hitting higher
No, shooting due east or due west, there is zero right Coriolis correction.

Coriolis is the difference in the speed the earth turns. The earth turns one revolution in 24 hrs. Along a latitude line, the earth's circumference is a different distance at each latitude so the earth travels further/faster in 24hrs at the equator than it does in Kansas. So, the bullet travels further east if fired north and travels less distance east if fired south causing the bullet to always hit right of the target. Shooting N/S the shooter and target are moving at different speeds when the bullet leaves the barrel. Shooting E/W, the shooter and target are both moving the same speed when the bullet leaves the barrel, therefore no left/right correction is required.
 
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I have not worried at all about correcting for spindrift or CE for shots under 900-1000 yards. Past 1000 yards, before using ballistic calculators, I'd correct for SD with a .5MOA correction at 1000+. The CE adjustment at 1000+ yards, shooting near west, +.25MOA, near east -.25MOA. No adjustment shooting north or south. This seemed to work well. I have shot with shooters that canted their reticle for spin drift, and it seemed to work fine. They said about three degrees of right cant with the reticle took care of SD. It doesn't help with CE corrections.
 
For target/steel shooting at ELR I understand why people would go through so much calculations and fuss. For hunting I typically do not have the time and simply range, estimate the wind, dial if necessary and shoot. Of course I am not confident enough to shoot at a critter at ELR. Exceptions are coyotes and other varmints.
 
No, shooting due east or due west, there is zero right Coriolis correction.
I disagree with this. Shooting West the target will move up and out from under the bullet flight causing impacts to be low. Shooting East the target is dropping and moving away causing the bullet to hit slightly high and to the right. I never worry about coriolis in a hunting rifle as it has little effect until you get out to extreme ranges. With updrafts, down drafts, and cross canyon winds, as well as aerodynamic jump, latitude, azmuth, time of flight and all of the other variables in any givin day I feel coriolis is the least important. Now for ELR guys shooting targets at 2k even 3k I'm sure it plays a major rule for that application. Hope this helps, Jason
 
Gravity is a constant and by far the strongest vector of bullet travel and it is always vertical. The other effects are small and vary. While some may choose otherwise, I would always keep my scope as vertical as possible and dial or hold for other variables per calculator. Also the vertical scope reticle should intersect the bore center. If not the line of flight will not be in the same vertical plane as the arc of travel. But then wind or other effect will curve that vertical plane of travel and bring it out of the arc between rifle and target. Now my head hurts. I don't see how you can calculate if you are not working off the vertical plane. Just my 2 cents.
 
I disagree with this. Shooting West the target will move up and out from under the bullet flight causing impacts to be low. Shooting East the target is dropping and moving away causing the bullet to hit slightly high and to the right. I never worry about coriolis in a hunting rifle as it has little effect until you get out to extreme ranges. With updrafts, down drafts, and cross canyon winds, as well as aerodyeast.namic jump, latitude, azmuth, time of flight and all of the other variables in any givin day I feel coriolis is the least important. Now for ELR guys shooting targets at 2k even 3k I'm sure it plays a major rule for that application. Hope this helps, Jason
Agree with the hitting high or low, I said zero "right" correction as he asked. He did not ask about elevation because he knew that answer already. Disagree with Coriolis causing a right hit if shooting east.
 
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I said zero "right"
I have 2 long range plates that are due East, one at 900 yards and one at 1350. Even with my Ultra mag's the 1350 due east will hit 6 to 7 inches to the right, even with correction for spin drift. If I forget to correct for spin drift I will miss the plate completely. I now correct for both and enjoy pounding that plate with a few different rifles. I need to try my BR4 with the enviro's turned on but haven't had the time, that would validate maybe. Just my findings as I shoot these 2 plates alot! cheers, Jason
 
If we are talking about long range shooting at steel or targets, carry on.

If we are talking hunting, I wonder if we have actually taken hunting to sniping?

I am beginning to wonder if we have evolved or devolved in the evolutionary food chain.

In our pursuit of one upping, I think we have jumped the proverbial shark.

Makes me wonder how archery hunters succeed with a stick and string.
 
Based on my very limited knowledge , and reading , and reading. Spin drift seems to cause little to no issue at the 100 to 500 yard range. A miss at a deer or elks lungs ,even at 700 yards, could be attributed more to my heavy excited breathing and my Hi Blood Pressure , and my Progressive glasses, then the fractions of an inch the spin drift would cause, at those hunting ranges. Speaking only for myself, The Exact Distance to the Target , THE WIND , the shooting angle, and the precession of my hand loads , the BC of the bullet I selected for the hunt, all would come to mind before Spin Drift. At L R shooting school the topic did not come up until we were at the 1200 yard range. Hitting steel was just fun and easy , but way to far for me to shoot at animals . Just my humble opinion.
 
If we are talking about long range shooting at steel or targets, carry on.

If we are talking hunting, I wonder if we have actually taken hunting to sniping?

I am beginning to wonder if we have evolved or devolved in the evolutionary food chain.

In our pursuit of one upping, I think we have jumped the proverbial shark.

Makes me wonder how archery hunters succeed with a stick and string.
Well the name of this forum is long range hunting. The more precise shot placement is with a stick and string or a modern rifle system the better for everyone including the game animal right? Is "sniping" any less valid or virtuous than hiding in ambush, wearing hi tech carbon lined clothes, washed in fancy scent eliminating detergent, climbing up in a tree stand constructed of steel and cammo painted to lay in wait for a buck that has been videoed, observed from the comfort of a living room sitting by the fire and patterned for two years so meticulously that you know within 15-20 minutes when he will likely walk under your stand within 10-25 yards for a broad side shot as he bows his head to take a last bit of c'mere deer?? Modern technical advances have made the "stick and string" season much different than primitive times as well. Of course, Same is true with modern rifle and muzzle loaders. Game management success in some states has made for a very robust population of animals that can sustain hunting seasons for all three methods. For me, I enjoy and prefer the challenge of wide open space, glassing for wary game and honing my skills with a modern firearm to place a first round into a vital zone at extended range. To do that well, I shoot and train on steel targets out to a mile in dynamic field scenarios, not a bench rest at a range. No shark being jumped here at all, just the passion of being a better rifleman to harvest game at the limit of my personal ability, which is generally about 800-1100 yards max and if the opportunity is there I will harvest game much closer. To each their own. :)
 
Hmmmm! Looks like we're considering the many variables involved in long range target acquisition! First off, I strongly believe in scope mount being Very level, plumb, and secure. Next, we must consider effects of Friction, Humidity, Wind, Gravity, Rifling (Twist), R or L spin, Spin-Drift, Coriolis, Velocity, and Bullet Shape on bullet Trajectory, especially at long range (beyond 500 yds.)! Few hunters will take a shot beyond 500 yds., especially on windy days! We always recommend zeroing scope at 400-500 yds., then adjusting back to 200 yds. This demonstrates to hunters that they Can make longer supported shots. The biggest spoiler for long range shots is almost always the Wind!
 
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