Another scope mounting question

[RichardK]

I've got a desert tech rifle with 34mm rings. The ring has it's own level at the bottom. My thoughts are that if I level the scope while the rings are also reading level I should be bang on? Keep in mind this is a 1000 yard + rifle.
Pics to help explain what I'm trying to say.

 

[Dmay]

In theory you are correct. However that is presuming that the cap on your turret is perfectly aligned with crosshairs. More precise would be to use a plumb-bob, align the vertical crosshair with it while the rifle is level.

 

[RichardK]

In theory you are correct. However that is presuming that the cap on your turret is perfectly aligned with crosshairs. More precise would be to use a plumb-bob, align the vertical crosshair with it while the rifle is level.

Maybe I'll try both. If it helps I'd assume a $4500 nightforce scope "should" have level caps, but you never know. Thanks

 

[rifleman338]

A piece of true flat bar that would clear the turret housing and your rail would work best. Make sure it touches flat on the bottom of the turret housing and put your level on it off to the side then just move it down on the rail and make them both level. I try not to depend on ring installed levels as they are never right.

 

[thegazelle]

RichardK, I have nothing substantive to add here, except congratulate you on your Father's Day gift! That rifle must be a thing of beauty!

 

[Alpheus]

Ignore that tiny bubble in the rings, it's useless. Make a plumb, just a hanging weight on a string. Level the rifle off the scope rail, and line up the reticle with the plumb. That will be close enough.

Having the scope levelled to the rifle is essentially inconsequential, what matters is the reticle/scope level with the target.

 

[RichardK]

RichardK, I have nothing substantive to add here, except congratulate you on your Father's Day gift! That rifle must be a thing of beauty!

Thank's Jer! And my place is always open for a quick few shot "sight in" it's a shame you're so far away. We just cant blast all day here unfortunately.

 

[BCBRAD]

If you find your dialing more windage than the ballistic chart requires (or less) then the vertical 'wire' in the scope may not be in line with the center of the bore.

The further out your group is , it will become more noticeable.

Do what others say but be prepared to make a fine tune somewhere along the way.

 

[medvedqc]

Ignore that tiny bubble in the rings, it's useless. Make a plumb, just a hanging weight on a string. Level the rifle off the scope rail, and line up the reticle with the plumb. That will be close enough.

Having the scope levelled to the rifle is essentially inconsequential, what matters is the reticle/scope level with the target.

if you do not level the rifle with the level of reticle/scope you may never hit the target without huge dialing ...

 

[thegazelle]

Thank's Jer! And my place is always open for a quick few shot "sight in" it's a shame you're so far away. We just cant blast all day here unfortunately.

Hey man, I would be delighted to swing by for "sight in" - no worries about the drive - I make a 2 hours drive each way to see the GF and her kids and have made that trip hundreds of times, so what's another 100KM each way? I actually just got a new rifle yesterday, a CZ and could definitely use some sighting in time, especially when I had no idea if I set up my new scope properly - I recently was checking out a Strikefire or something like that and thought that the small end is where you put your eye (which has always what my cheapo scopes have been). LGS operator turned it around on me - I am pretty clueless with optics). Thanks for the invite. Happy to reload your beer supply too (I crack up when I type this as I am not a drinker, so don't even know what I am saying...lol). I actually got a case of Moosehead (think that's what it's called) for the guys who got me out of the mud the first time at the camp but the second time I didn't see them... Kids and I had an awesome time!!

 

[Alpheus]

if you do not level the rifle with the level of reticle/scope you may never hit the target without huge dialing ...

I used to think that too, until I did a test.

Deliberately cant the scope on your rifle, the more the better. Like this:

Keeping the reticle level with the target, zero at 100 yards. Now do a tracking/tall target test, dialing up a few moa/mils, shoot a few rounds, dial more, until you have this:

You will see that the results are identical to if you had done it with the scope and rifle levelled to each other. In other words, once zeroed, the scope-rifle level doesn't matter.

 

[medvedqc]

I used to think that too, until I did a test.

Deliberately cant the scope on your rifle, the more the better. Like this:

Keeping the reticle level with the target, zero at 100 yards. Now do a tracking/tall target test, dialing up a few moa/mils, shoot a few rounds, dial more, until you have this:

You will see that the results are identical to if you had done it with the scope and rifle levelled to each other. In other words, once zeroed, the scope-rifle level doesn't matter.

please try that at longer distance ...

 

[cartwheel]

I have one scope that has a canted reticle (burns my ass, but still using it). Found this out doing the plumb-bob level method to align the scope and struggling before figured out the issue. The rifle needs to be leveled to the elevation turret as this is what moves the reticle vertically regardless of what the reticle shows. If this is off or there is a cant in the rifle there will be windage added to the elevation- it is geometry. The scope-rifle level does matter- just maybe not that much at close range.

One thing to check is the accuracy of the levels you are using- sometimes those little things aren't so good and it would be better not to have them.

 

[Alpheus]

please try that at longer distance ...

Why would it be different? It won't, but I am curious as to your reasoning.

If this is off or there is a cant in the rifle there will be windage added to the elevation- it is geometry. The scope-rifle level does matter- just maybe not that much at close range.

If there is left cant to the scope, you will miss low and left. Right cant, miss low and right

 

[medvedqc]

Why would it be different? It won't, but I am curious as to your reasoning.



If there is left cant to the scope, you will miss low and left. Right cant, miss low and right

because we tried long time ago with the armorer (we were not allowed to modify the mount way (only settings and adjustment)) when i was in the army: it was only with the frf1 and a fixed apx x3.85 but it does make a different at longer distance maybe due to the scope. we tried only up to 600 meters. maybe due to the combo rifle scope and the specific reticle but i doubt it was only that: like you i said it will make no differences and it should not ... our buddy of the marine had the fixed sb 6x but we were not able to try that one to see the differences.

 

[1-trident-1]

its all fun and games till the bullet begins to drop, thats why the longer ranges that were available, but were not used for the photos.

 

[350 Mag]

As mentioned above.

Levels are pretty much usesless.

Hang a plumbline.

Make sure the vertical reticle us plumb.

Lock scope level to that.

How you shoulder your rifle will dictate whether the action is level or canted....BUT a slighty canted action doesnt degrade accuracy.

Confirm by shooting groups and adjust the tracking up or down to make sure scope is tracking properly.

 

[Dogleg]

please try that at longer distance ...

Exactly. It will crossfire.

 

[Alpheus]

Exactly. It will crossfire.

I don't think you realize how little that matters.

Lets do the math. Pretend there is a 5 degree angle between the vertical cross-hair and the bore of the barrel. How much does that offset the bore to the left or right? Depends on the height over bore. Lets say that is 2 inches.
Doing the math results in an offset of 0.175".

Diagram is looking from directly behind the scope, cross-hairs level.

Now since we zeroed at 100yds, the axis of the bore and the axis of the scope aren't parallel, they intersect at 100yds.

Diagram is looking from the top.

X equals 0.00278521 degrees.

So at 200yds, the point of impact will be 0.175" to the left of the point of aim. So yes, technically, you will "crossfire". 0.175" @ 200yds equals 0.0836 MOA
At 300 yds, the point of impact will be 0.35" to the left of the point of aim. 0.1114 MOA
At 400 yds, the point of impact will be 0.525" to the left of the point of aim. 0.1253 MOA
At 500 yds, the point of impact will be 0.7" to the left of the point of aim. 0.1337 MOA
......
At 1000yds, the point of impact will be 1.575" to the left of the point of aim. 0.1456 MOA

So much less than 1 click on the 1/4th moa windage turret. Or a fraction over 1 click of a 1/8th moa scope.
Like I said, inconsequential. If you can read the wind to the degree that you can shoot the difference of 1.5" at 1000yds, you shouldn't be down here shooting with us mere mortals.

A simple level over the scope rail and a plumb line for the reticle will get you close enough that you will never notice any error.