Scope Canting

[Tall]

Yes, going to the range in the morning. I just learned a the quickest method from a sniper team leader. When mounting the scope you take a straight edge, (like my caliper) and place between the rail mounted on my gun and the flat spot on the bottom of the scope. twist up and adjust the scope until the two surfaces are completely flush and no daylight.

I checked this method and it appears I am perfect. I am feeling good about my scope now. Can't wait to shoot some groups now.

 

[Broz]

Yes, going to the range in the morning. I just learned a the quickest method from a sniper team leader. When mounting the scope you take a straight edge, (like my caliper) and place between the rail mounted on my gun and the flat spot on the bottom of the scope. twist up and adjust the scope until the two surfaces are completely flush and no daylight.

I checked this method and it appears I am perfect. I am feeling good about my scope now. Can't wait to shoot some groups now.

That is a good beginning. But does not insure the reticle is mounted inside the scope tube plumb. Nor does it assure that went you dial in for a shot that the reticle will track true to plumb either. I still feel the best method is to true the reticle to a plumb line at 50 to 80 yards while keeping your rifles level leveled up. Then the shoot up the line test while dialing up 30 moa is the final step.

Just come in from doing another one myself.

Jeff

 

[oldmossy]

So is a person better off sighting their rifle in a touch to the left of center at 200, or canting the scope to try and take care of the spin drift? My rifle looks to have 2.6" of spin drift at 1000 yards going by G7 calculator. (that is if I got all info entered correctly)

I know 2.6" isn't much, but I would prefer to not have to worry about it. Together with earth rotation, looks like i'd be close to 4.8" right at 1000 yds shooting north or south.

 

[Michael Eichele]

So is a person better off sighting their rifle in a touch to the left of center at 200, or canting the scope to try and take care of the spin drift? My rifle looks to have 2.6" of spin drift at 1000 yards going by G7 calculator. (that is if I got all info entered correctly)

I know 2.6" isn't much, but I would prefer to not have to worry about it. Together with earth rotation, looks like i'd be close to 4.8" right at 1000 yds shooting north or south.

What calculator are you using? 4.8" seems low for most set ups.

 

[tmmcampbell]

Doesn't spin drift depend on whether your shooting north south vs east west?

 

[Michael Eichele]

For spin drift no. Spin drift is a result of air pressure. When a bullet is in mid air the nose points slightly off center in the direction it is rotating. Since most barrels have a right hand twist, the nose of the bullet points slightly right which puts more air pressure against the left side of the bullet than the right forcing it to the right. A bullet's length, stability factor, rpm and time of flight come into play here.

You may be thinking about the coriolis effect. This will also cause objects to appear to deflect. In the northern hemisphere it will always appear to impact right. North, south, east or west makes little to no difference regarding a right hand impact. Since I live in the northern part of the northern hemisphere and I use right hand twist barrels I see between 8-12" of combined SD+CE depending on which caliber and load I'm using. Shooting east versus west, the coriolis effect affects your vertical. North versus south is of no consequence vertically.

 

[oldmossy]

I'm using the G7 calculator by gunwerks.