Leveling your scope

[HUAINAMACHERO]

I have always tried to be as accurate as possible in every way about hunting.
When I install a scope to a rifle, I first put the rifle in a stable and straight position, and then 20 or 30 feet away I put a level so I have an horizontal reference, and behind it I put a plummet with a black string attached for a vertical line of reference. As shown in picture. And then get the scope straight with the vertical and horizontal line.
Dont know if I should do this with the minimum or maximum magnification in the scope to make it more precise???
Thanks for the comments.

 

[Jerry D]

I would think the way to make it the most accurate would be that so the level just touches both edges of the scope. That way you can line the entire cross hair up with the edge of the level. The longer the level the more precise you will get.

Adjust the magnification of the scope accordingly. You may also then have to increase or decrease the distance in which you look at the + created by the level/plumb bob.

After this you can do simple cant tests by firing the rifle and raising the vertical adjustment while aiming at the same aim point. If the bullets rise straight up your good, if they go up and a tad left/right then you need to twist your scope a tad.

 

[Kevin Cram]

I level scopes very similiar. I hold rifle securely in a padded vise. I then have a 4' level out about 50 yards. I use a small magnetic level that just fits inside my ejection port and lays across the raceways. I use this to make sure the rifle is level, then I run the cross hairs across the top of the level exactly making the scope level to the raceways. I keep checking both levels as I slowly start tightening each ring cap down. I've had very good success doing it this way.

 

[woods]

Armando

What you are doing is great but it is only part of the process. You also need to level the crosshairs like this while the rifle is uncanted and then be able to duplicate holding the crosshairs level while shooting in the field.

I use a EXD ENGINEERING VERTICAL RETICLE INSTRUMENT at Brownells

I set the rifle in a vise and use the EXD to align the center of the bore and center of the scope by rotating the rifle until the bubble is level and lock the rifle in place in the vise. When you do that the rifle is perfectly uncanted. While it is locked down you rotate the scope while sighting on a level or vertical plumb bob as you described until the reticle is level also. Now when you lock down the rings with everything level then the reticle is perfectly level when the rifle is uncanted.

Now you need to duplicate this uncanted position in the field. There are several anti-cant devices but the one I use is the Scoplevel Anti Cant Leveling Device

which folds down when not in use

but which you can still see when looking through the scope

When you hold the bubble level you are taking all the cant out of your rifle position and holding your reticle level.

 

[kmad61]

Go buy the Wheeler Engineering scope level kit.I have installed numerous scope using this and it works like a charm.$20 from Cabelas.

 

[Kevin Cram]

I got the Wheeler Level Level Level. I really just wanted their magnetic level for the raceway. I set a scope up using the instructions provided. Level raceways and lay the other level across the turret (cap removed) and rotate scope until both levels are reading level with each other.

I then put my 4' level out at 50 yards to see how close my cross hairs were level with the action raceways. With the raceways level a look through the scope showed **** near an inch canted at 50 yards. That's terrible. I re-checked the level on the turret it was reading dead level.

The Wheeler scope level may be ok for the home tinkerer who will only be shooting 100 yards in the woods and not using the turrets for elevation changes, but for long range use it's a piece of crap.

 

[AJ Peacock]

I use the Wheeler level in the raceways and I hang a plumb bob on a visible string at 100yds. Then I know it's all good.

AJ

 

[Varmint Hunter]

How do you (anyone) know that the raceways are perpendicular to the verticle line which is found between the center of the bore and the center of the scope? Isn't the use of the raceways (to determine when the rifle is plumb) making an ASSUMPTION by which everything else is based? Just asking.

The EXD Engineering tool looks like the only way to properly establish that the rifle is, in fact, plumb before rotating the scope to align with a known plumb or horizontal line. I've never used the EXD but the principal by which it works seems to make sense.

Placing a tiny bubble level on any flat surface of the gun doesn't seem to be a very sound way to go forward IMO. Hmmmmm

 

[AJ Peacock]

How do you (anyone) know that the raceways are perpendicular to the verticle line which is found between the center of the bore and the center of the scope? Isn't the use of the raceways (to determine when the rifle is plimb) making an ASSUMPTION by which everything else is based? Just asking.

The EXD Engineering tool looks like the only way to properly establish that the rifle is, in fact, plumb before rotating the scope to align with a known plumb or horizontal line. I've never used the EXD but the principal by which it works makes seems to make sense.

Placing a tiny bubble level on any flat surface of the gun doesn't seem to be a very sound way to go forward IMO. Hmmmmm

As long as the scope is very close to directly above the center line of the bore and is shot in that position, any off axis error will be very small. For example, if the raceways where cocked at 5 degrees (which would be a lot), the missalignment would be a very small fraction of an inch. The bullet would start out that very small fraction of an inch to the side of the line of the scope (around 1/10th inch in this example, with scope height of 1.5" it would be a misalignment of .13"). So if I sighted in at 500 yards this rifle would shoot 1/10th inch to the side at 1000yds (discounting spin drift etc).

AJ

 

[Varmint Hunter]

Do rifle manufacturers design the receivers so that the raceways are parrallel to the theoritical flat of the receiver top?

Is it a sound practice to put a bubble level aross the flat of a scope base to set the rifle in a plumb/level position prior to rotating the scope for correct reticle position?

I've seen shooters put a bubble level on a turret cap to determine when the scope was in proper rotation but I would have little confidence in using this methed.

 

[AJ Peacock]

Do rifle manufacturers design the receivers so that the raceways are parrallel to the theoritical flat of the receiver top?

Is it a sound practice to put a bubble level aross the flat of a scope base to set the rifle in a plumb/level position prior to rotating the scope for correct reticle position?

I've seen shooters put a bubble level on a turret cap to determine when the scope was in proper rotation but I would have little confidence in using this methed.

Yes and Yes.

The scope base being level is dependent on the mounting screws being drilled in the proper alignment. I've seen them in misalignment, but not very often.

I don't trust the turret caps either, I've rarely found them to be square with the reticle. I believe this is due in part to the threading.

AJ

 

[mattj]

I may be completely wrong here (but I don't think I am). If I am, I'd appreciate if somebody could tell me why, because it means I have a trouble somewhere in my personal integrated understanding of how things work... I guess I might be more confident if my understanding didn't seem to run counter to the 'conventional wisdom'...

But provided that you have a way to consistently get the reticle lined up so that 'up' is really the gravitational 'up' when you take the shot.... I don't see how the perfect alignment of the scope to the action should matter, provided that its positioning does not affect your ability to get into a comfortable and consistent shooting position (with the reticle aligned properly to vertical).

I was originally a fan of the scope-rail mounted anti-cant device (assuming everything lined up so that it was 'level' when the action/aligned scope are level) -- but I recently obtained a scope-ring style mounted anti-cant device, and to my mind, it makes everything much easier:

1) Mount scope, getting it as close as you can to "vertical" with respect to the action, but not worrying about buying a bunch of expensive stuff or taking half a day to do it -- just basically eyeball it to the best of your ability... loosely attach a scope-mounted anti-cant device.

2) Using a vice, sandbacks, or something steady, point rifle/scope at a plumb line 100+ yards away, and align the RIFLE until the reticle is lined up with the plumb line.

3) Adjust the anti-cant device so the "bubble" is centered when the reticle is properly vertically aligned -- tighten it down.

4) After tightening, ensure the bubble is still centered with the reticle aligned to the plumb line.

DONE....

When shooting, I get roughly on target, check the bubble, tilt the rifle until the anti-cant indicates it is level, lock down the pod-loc on my bipod, confirm still level... and proceed with everything else.

My point being I guess that I don't see the point of going to extreme pains to ensure the scope reticle is PERFECTLY aligned with respect to the action. In fact, my feeling is that the *ideal* alignment of the reticle with respect to the action -- ie, the alignment that allows the most natural, comfortable body position in which the reticle is aligned to gravity, is probably NOT a perfect reticle/action alignment. I haven't bothered to pursue this "perfect cant" yet, but its on my list of things to try sometime...

In terms of bullet trajectory, the bullet doesn't give a **** about the orientation of your rifle once it leaves the barrel. The reticle/action alignment will of course affect your initial zero -- but once zeroed-in (with a properly aligned rifle to gravity), the fact that your rifle is canted does not matter provided that it is aligned the same way every time (which is where the anti-cant device comes in).

The only place I can see action alignment really mattering (given reticle alignment and that shooting position is not compromised) is with certain muzzle brakes that are explicitly trying to counteract muzzle rise by disproportionately venting gas in a certain direction (ie, up) -- in this situation a canted rifle could add a weird "sideways" component to recoil which could make things interesting... but I reckon it would take a significant amount of rifle cant for this to even be noticed (to the shooter, or on paper).

So that's my take... and like I said, if I'm missing some big reason why the reticle needs to be perfectly aligned to the rifle, I'd really like to know what it is I am missing.

Thanks,
-Matt

 

[Kevin Cram]

That is a good question Varmint Hunter, but how do we know the outside of the barrel is true to the centerline of the bore with the EXD. The EXD centers itself in a V-block to the ouside of the barrel and to the bell of the scope. How are either of these positively true to centerline of the bore? How do we know the bore is cut exactly through the center and not off the one side. If you put centers in each end of a barrel and spin the barrel in a lathe you will see that alot of barrels run out of round from bore to outside.

The raceways are either broached or wire edm'd parrallel to each other during machining. The guard screws are then drilled and tapped perpendicular to the raceways. The scope base holes are then drilled and tapped in reference to the guard screws. The raceways give you a parrallel surface from which to reference the reticle of the scope in the same plane.

 

[AJ Peacock]

Matt,

I believe you are correct in your thinking. If the axis of the scope and the barrel are significantly out of alignment (from a vertical perspective) the bullet will only be in the axis of the scope at the sightin distance. What you describe will work fine, the main thing is having the reticle vertical when you fire the shot.

AJ