Do Not Mount Your Scope Level

[JustMe2]

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

7Rum, are you shooting "true" east or magnetic east? Coriolis is calculated using latitude lines that are drawn true E/W. There is magnetic variation that must be eliminated from your E/W aiming to arrive at "true" E/W. Depending on your geographic location, the magnetic variation could be very large. Again to see any significant Coriolis, you'd have to be shooting ELR and probably not hunting game, just targets or the enemy. LOL

 

[Dragoon300]

The answer to the original question is simple, NO! Never! Absolutely not!

Do not add any intentionally induced variables to an already complex equation with expectations of getting a quicker solution!

Select the best rifle, optic and mounting system for your application that you can afford. Have the optic and mount installed by a competent person if you are not qualified to do so yourself. Mount your optic with its reticle as vertically aligned as possible. Install a level on your rifle and use it. Zero at 100 yards or meters, which ever you prefer. Know the velocity and ballistics of your rifle and ammunition. Have a proven ballistic calculator, environmental instrument and rangefinder, and know how to use all of them. With proper instruction in the fundamentals of marksmanship, and further instruction in long range precision shooting you may be able to hit your desired target. With practice, experience and the right circumstances you may be able to take some short cuts to make certain shots, but first of all know know your equipment well, and the basic fundamentals.

 

[WildRose]

In a previous thread, a forum member stated he intentionally sighted in his scope to hit the target to the left of the 100yd bullseye to compensate for spin drift and Coriolis at longer ranges.

Question: what are your views about using a tall target to mount your scope with an intentional calibrated cant and not level?

Procedure: Draw 2 lines on a tall target, one line being straight up/down level like is normally done, then draw a 2nd line in a "V" shape to the left originating at the 100 yd zero. As the 2nd line is drawn upward from the 100 yd zero, it should get further and further away from the level line. The result being at the 1500 yd point on the target the "V" line would be maybe 3-10" to the left of the center/level line.

Now place the rifle level in a vise and zeroed/sighted-in at the tall target placed at 100 yds. Next, loosen the scope and cant it, keeping the rifle level, to align the scope reticle with the "V" line and not the level line. This would put an intentional ballistically calculated cant in the scope to compensate for your rifle's spin drift and Coriolis as you dial the scope upwards. Now during a hunting situation, you'd only have to compensate for wind holds and not worry about adding spin drift or Coriolis.

So, what are your opinions of putting an intentional cant in your scope while mounting it?

You're going to screw more things up than you'll ever correct intentionally not getting your vertical crosshair plumb.

Maybe if you only shoot on one range and from the same direction all the time would it make sense but inside of 1,000yds your Coriolis adjustment is negligible anyhow.

 

[Reelamin]

So given say an 800yd max hunting range (won't shoot further at game than that) where is a good "zero" I was figuring 250-300yd is that a good zero to keep?

I don't like to dial if I don't have to. For me it is different with different scope, scope reticle. My current LR hunting gun (300Rum 180AB/180BT @3400) only has a standard fine duplex. I always have it zeroed at 375yds or 4" high at 100. I have to dial when my aiming point is off the hair. Deer/Antelope after 450, Elk 500. My second new one (28N 160AB @3400) has a Tree Reticle and I can hold to 1000 by computer. So far only held to 900, and I finally got some bullets to finish it off. I have not killed anything with it since I hunted with Bow/Muzzle last year. The latest one (338 Edge) on paper I should be able to hold to 1000 by computer. I have no idea what it will actually do since this week I start load development this week.