Scope leveling

[J E Custom]

One thing that I have noticed is that the various methods of leveling a rifle often don't agree with each other.
If you put a level across the raceways and another on the top of the receiver, or atop of a pic rail, or atop of any other point of reference they rarely agree.
It seems to me that a level rifle should have the center of the optics directly over and plumb with the center of the bore. Not much else should matter. There is a tool that indicates this but I question its accuracy. If you use the device and put a machinist's level across the raceways they are, at times, not even close.
Leveling a scope is fairly easy but determining when a rifle is perfectly level or plumb before you do so is the difficult part.

I totally agree that there are differences when you use the scope caps. top of mounts or other machined surfaces compared to the action rails. The rails are the most accurate point to level from because they are machined with the receiver level to the rest of the action and perpendicular and parallel to the bore.
To assure that your level is correct you can swap ends with it and it should not change (All levels and measuring instruments should be checked periodically to assure you that they are correct)

Once you have the rails perfectly level, everything else should be leveled off this. The reason I like the optical level process is that eliminates the error between systems and the eye location error.

The more accurate the leveling system, the more accurate the turret changes will be.

J E CUSTOM

 

[Mikecr]

Leveling a scope is fairly easy but determining when a rifle is perfectly level or plumb before you do so is the difficult part.

That's because there is no real reference set from the ground up. The stock can be anything but level. Or in other words -what is a level stock?
The action is set in stock bedding, and what would that action be level to? The stock?
If this much plus bases & rings is square, the scope is likely not..

Well luckily we don't aim with anything underneath our aimpoint.
So all that matters in the end is that our aimpoint (POA) is plumb to our result (POI).
And you have to shoot this much, as even our load tune affects it.

Find plumb for your aimpoint (the scope's provided aimpoint), fix this to the scope (all that matters)(not the caps, rings, or rails), and you can move the scope from gun to gun and be very close to plumb in your shooting. All that's left is to do some shooting for the final tweaks.
The best device for setting this is a 'ScopLevel'. It mounts to the scope body & flips up into view -for your shooting eye- dead behind POA as well.

 

[J E Custom]

Not to start an argument but that is exactly what the Action rails do. If you are directly Perpendicular to the rails, and vertical over the bore it doesn't matter if the stock is not perfectly centered to the bore. In fact it is almost impossible to get the stock perfectly vertical even though it is bedded.

If the action and bore are on the same center line as the scope base mounting screws, and you level the scope to this. the elevation will/should not effect the windage as it is increased.

I have seen rifles scopes/sites leveled using the stock and it doesn't work if you shoot multiple distances from 200 yards to 1000 yards or farther.The stock doesn't effect the change in windage as you elevate the vertical turret, but any misalignment of the scope vertical center line to the bore vertical does.

If you hunt with one zero, none of this realy matters that much. If the scope is vertically level with the bore the line of site and the line of bore converge at the POI and forms a triangle that is also plum/vertical.

Just saying

J E CUSTOM

 

[dfanonymous]

People keep in mind you barrel is tilted upward. bring it back to basics and remember that bullets arch (max ordinate) and drop. if your scope is even on the plumb line but you rifle barrel, which should be square to the receiver is not...then your scope and rifle are not sync'd in leveling and thus not level to the how the bullet travels. if you rifle is level and the reticle is not level to a plumb line, they are not synchronized and you're not level.

 

[therifleman556]

Your barrel is not tilted upward; your sighting plane is angled downward in relation to the bore line. The plumb line referenced represents an infinite number of potential points of impact along the bullet's trajectory. Ensuring that your reticle's vertical stadia is parallel to the plumb line and thereafter once adjustments are made is your assurance that POA matches POI and that you're not going to inadvertantly cause a minor windage adjustment when you dial up for distance. This assumes that you're not canting the rifle of course.

 

[dfanonymous]

Your barrel is not tilted upward; your sighting plane is angled downward in relation to the bore line. The plumb line referenced represents an infinite number of potential points of impact along the bullet's trajectory. Ensuring that your reticle's vertical stadia is parallel to the plumb line and thereafter once adjustments are made is your assurance that POA matches POI and that you're not going to inadvertantly cause a minor windage adjustment when you dial up for distance. This assumes that you're not canting the rifle of course.

Yeah my bad, i didn't mean the barrel was machined and installed angled but that it was on a position of the barrel would be the beginging of the parabola that would be the begging of the billets trajectory. Thus if you sight alignment is downward the barrel is upward.

 

[Mike 338]

1) Align the reticle perpendicular to the bore.
2) Align the reticle/rifle to plumb.

This simple tool works great for #1
https://www.highpoweroptics.com/ringtrue™-reticle-alignment-tool-p-16566.html

For #2, I hang a string with a small weight (plumb line) from a window sill. It hangs almost to the floor. Then put the rifle in gun caddy and face it backwards so the barrel points away from the wall. Then get a flashlight and turn out the lights. Shine the flashlight through the front of the scope and it will superimpose the reticle on the wall. Have your bubble level already on the scope but loose enough to adjust. Adjust the rifle so your image of the reticle lines up with the plumb line and adjust you bubble level so it's showing "level".

Now your scope is aligned to the bore and your bubble level prevents you from canting the whole rifle one way or the other.

 

[Mikecr]

Keep in mind also that a reticle often is not, and may not need to be, plumb to anything. That is, if you're dialing elevation and holding into wind & mirage(like I do),
a reticle can be a simple dot.
I don't like dot aim points, as I feel they wonder to the eye. I aim only with a crosshair intersection. I know with many scopes(even high dollar) the actual crosshair is not square to elevation adjustment. There is a manufacturing tolerance there.

I only mention this because it's a decision point about what you're going to choose, when you can't get every item to align. To simply declare that everything should be square,, well, that is often not really the case and sometimes you have to play with cards dealt. You can, no problem.

 

[gohring3006]

I get a consistent hold on the rifle, set up a plum line on a tall target. I then get the crosshairs plum with the line using my consistent hold, then dial on the target, turning the scope until it tracks strait up. I know some like getting the rifle and scope, "level" with each other, but I don't hold most of my rifles "level" while shooting so it doesn't help me at all. It just causes me to fight the rifle rather than have a natural point of aim. The amount of cant in the rifle (not the scope) that has influence on my shooting at long range is less than what wind would be, and can't be distinguished between the two. Get your comfortable hold, get the scope to track strait up and then set your anticant level, or if you don't dial and use the reticle, get your reticle hold to impact strait up and set anticant level. With most but the very high end scopes, you rarely get tracking and reticles true with each other.

 

[tmmcampbell]

Do all of the above then shoot a tall target test. See if they match vertically. It will also tell you if your scope tracks true.

 

[Pete FARR]

Try using one of these devices.
https://www.inventeng.com/scope-setter.asp
or
Holland's Scope Mounting Fixture
https://www.hollandguns.com/