How to align the axis of the scope with the axis of the bore of the rifle?

[HandB]

Hi Everyone,

I notice that with two piece scope mounts many people advocate lapping the scope rings and testing with conical pointed rods to make sure they line up with each other, as shown here: Scope Mounting: How to Align Scope Rings for Accuracy - Special Reports Article

However this method doesn't necessarily ensure the axis of the scope is horizontally aligned with the axis of the bore, as the scope rings could be perfectly aligned with each other yet run off to one side or the other relative to the bore of the rifle. Therefore I am curious to know what are your favourite methods for checking the axis of the scope is horizontally aligned with the axis of the bore?

Thank you!

 

[Shootgun]

I haven’t got this problem as i’m using a rail mounted scope which seats on the barrel, not on the action.

 

[Selous]

Lapping the rings is more to prevent crimping of the scope tube and increase contact area between rings and tube as far as I know. Alignment with the bore is dependent on how accurately the base screw holes are drilled in relation to bore axis. If these are off centre then to scope will be poorly aligned regardless of type of base

 

[Colonel]

If you’re asking how I align the horizontal cross hair with the bore, I use a shot saver. Once the shot saver is fitted in to the bore then the scope is rotated and the shot saver is moved so that the horizontal lines align together then it hase to be spot on.

 

[Outback]

If you were to mechanically center your scope windage , mount the scope , then bore sight to a plumb line and look through the scope would this show it .

 

[Tim.243]

Hi Everyone,

I notice that with two piece scope mounts many people advocate lapping the scope rings and testing with conical pointed rods to make sure they line up with each other, as shown here: Scope Mounting: How to Align Scope Rings for Accuracy - Special Reports Article

However this method doesn't necessarily ensure the axis of the scope is horizontally aligned with the axis of the bore, as the scope rings could be perfectly aligned with each other yet run off to one side or the other relative to the bore of the rifle. Therefore I am curious to know what are your favourite methods for checking the axis of the scope is horizontally aligned with the axis of the bore?

Thank you!

You are amusing that your barrel is true to the action....! Having 30mm tube scopes I used a piece of 30mm ground stock bar to nip up all the mounts after working out where I wanted them.
All the mounts settle around the stock bar then loosen them off and repeat.
No torque driver just feel.....

Tim.243

 

[Klenchblaize]

Hi Everyone,

I notice that with two piece scope mounts many people advocate lapping the scope rings and testing with conical pointed rods to make sure they line up with each other, as shown here: Scope Mounting: How to Align Scope Rings for Accuracy - Special Reports Article

However this method doesn't necessarily ensure the axis of the scope is horizontally aligned with the axis of the bore, as the scope rings could be perfectly aligned with each other yet run off to one side or the other relative to the bore of the rifle. Therefore I am curious to know what are your favourite methods for checking the axis of the scope is horizontally aligned with the axis of the bore?

Thank you!

Your choice of mounts & rings will determine the ease with which this may be achieved if I've understood the question correctly:

a. First center your scope's windage crosshair by establishing total number of clicks and then setting at the mid point.
b. Choose the following type of mount & rings that will permit the alignment you refer to, including zeroing (within one 1 or 2 scope adjustment windage clicks), by suitable adjustment of the left & right cone screw in both the front and rear mount.

S&K or Conetrol do very nice sets as per the below picture:

There are of course other mounting systems that permit such adjustment but many only allow adjustment of the rear ring.

K

 

[Colonel]

To align my scope parallel the the bore I first check that the windage turret is central and then bore sight at an object about 100yds out.

 

[CarlW]

To align my scope parallel the the bore I first check that the windage turret is central and then bore sight at an object about 100yds out.

I don't think this is what the OP is asking. See Klenchblaize's answer above for what I think the OP means.

However, there really are other things to spend one's time worrying about instead.

 

[HandB]

I've just been experimenting and it turns out that with two flashlights, one large, one small it is possible to do a basic check of bore/scope axis alignment. First I mounted the rifle in a vice aiming at a blank wall. Then I centred the crosshairs in the scope by counting clicks, then mounted the scope backwards. Then turned off the room lights and positioned a small flashlight shining down the barrel from the breech so that it shone a beam on the wall out of the muzzle. The rifling forms concentric circles which facilitate alignment. Then I shone a large flashlight down the scope from the objective lens end, so that the cross hair is projected on the wall. This allowed me to see that the cross hair is projected slightly to the right of the centre spot of the barrel projection. So I turned the mounts around and the cross hair moved left so that it touched the edge of the barrel projection. It's not perfect but not bad either.

 

[John Gryphon]

New #10
I've just been experimenting and it turns out that with two flashlights, one large, one small it is possible to do a basic check of bore/scope axis alignment. First I mounted the rifle in a vice aiming at a blank wall. Then I centred the crosshairs in the scope by counting clicks, then mounted the scope backwards. Then turned off the room lights and positioned a small flashlight shining down the barrel from the breech so that it shone a beam on the wall out of the muzzle. The rifling forms concentric circles which facilitate alignment. Then I shone a large flashlight down the scope from the objective lens end, so that the cross hair is projected on the wall. This allowed me to see that the cross hair is projected slightly to the right of the centre spot of the barrel projection. So I turned the mounts around and the cross hair moved left so that it touched the edge of the barrel projection. It's not perfect but not bad either.

JUst reading that took too long let alone doing it ha ha.

 

[palo]

I fitted a few scopes recently for myself and a few friends. All were picatinny type.
I did centre the Windage adjustment and when boresighting before firing a shot I could see that the Windage was way off. I did mess about turning the rings around and switching the back and front rings around until I got it close enough.
I managed to get them all zerod with minimal scope adjustment.

 

[Cyres]

Firstly center windage and elevation. I always use Burris Zee Signature rings which by using the various inserted allow you get pretty close to POI. I then bore sight and align scope to POI with inserts and then fine tune with elevation and windage.

As for determining if the barrel is centered too the receiver I don't know how its done. The critical bit would be drilling the mounting holes in the receiver.

D

 

[enfieldspares]

A four foot length of wool or white string and an Arlesey bomb. Used as a plumbline. Or a convenient true perpendicular to the horizontal door jamb or window frame. Just clamp or pack the rifle so that it is aligned properly upright. That you judge by eye. Then boresight the rifle onto that plumbline or jamb. Then adjust the 'scope so that, too, aligns with the plumbline or jamb.

The other way if you can't "plumb" the thing is to come back from, or stand away from, the rear of the weapon and align the vertical crosshair on your rifle (by eye judgement) with the rifle's sear that is visible by looking through the boltway. So the sear can do more than just release the striker on the bolt! It can help you align the 'scope.

In practical terms this last works as well as any. Then simply boresight by looking at a small object through the barrel and adjust windage on the 'scope left and right if using Redfield type "turn in" mounts accordingly.

 

[enfieldspares]

Using the align with the sear method you can pretty much do this with the rifle held up to the shoulder but not quite yet held into the shoulder as if you were just about to take a standing shot.

 

[Klenchblaize]

As for determining if the barrel is centered too the receiver I don't know how its done. The critical bit would be drilling the mounting holes in the receiver. D

Or have the ability to shift the front & back rings (within their base) left or right to compensate for any minor off-center mounting holes:

K