How do I adjust scope bubble level

[Bigdad123]

I am going to shoot a Tall Target Test per Litz's video this weekend and want to adjust the bubble level on my scope if necessary.

The bubble level is attached to my scope externally, its not internal to the scope. The reticle is aligned with the rifle action. When I installed the scope, I aligned the reticle with a plumb bob and a level on the rifle action. Then I aligned the scope bubble with that.

My question is, which direction do I tilt the scope bubble level if my low and high groups are not perfectly lined up? My thought is that I would tilt the scope bubble level to the right if my high group is left of the low group. Am I correct?

 

[Bigdad123]

Anyone know how to do this?

 

[hogpatrol]

Help us out here. Why worry about something that may not occur? Best to do the test & then figure out where to make adjustments.

 

[Bigdad123]

I've got a few rifles I want to do this with and at least one will probably be off. I don't want to spend a lot of time/ammo adjusting the wrong way. I was hoping someone that had done this before and could provide a quick answer.

 

[orbitup]

If you've leveled your scope with a plumb bob and it isn't tracking correctly then you need a new scope. Or you could just adjust your ballistic tables to compensate.

 

[Sheldon N]

Assuming everything was done correctly with your reticle perfectly aligned with the true vertical plumb line on the tall target when you shot it, then the results are telling you that the reticle is canted slightly. My thought would be to do this....

Shoot the tall target test again to verify. Assuming that the results repeat, then I'd rotate the rifle ever so slightly so that the reticle leaned a little bit to the right, pulling the point of impact of the upper group back onto the vertical line. You'd want the bottom edge of the reticle to go through the bottom 0 mil point on the line, then the top edge to be the corrected POI. Once you had this positioned, I would re-set the bubble level on your scope so that it read dead level when the reticle had that tiny bit of "corrected" angle to it.

Doing this would make your scope bubble level track perfectly true with the internal elevation of your turrets. You could then go out and shoot in the field, trusting that the bubble level on your scope was the perfect reference for keeping the gun properly aligned to gravity when shooting and dialing for elevation.

 

[pnw]

Reticle Perpendicularity - Holland's Shooters Supply this may also help answer your question

 

[Bigdad123]

thanks everyone

 

[Sheldon N]

Reticle Perpendicularity - Holland's Shooters Supply this may also help answer your question

Just as an FYI to anyone else who might read this thread, there are an awful lot of inaccuracies in that article.

 

[Bigdad123]

Thanks for your recommendation on how to align the bubble Sheldon, makes total sense.

 

[moondog]

Got a good tip on this from a guy at a match last week. Clamp your rifle up level.
I use a vice with barrel jaws. Mount your scope loose in the rings. Dim the lights and
shine a flashlight thru the Objective. Your reticle will show on the wall (20 ft away)
Hang a Plumb Bob and square up the scope. Now you can adjust your level.
I guess if you have a target dot, Your F**%ed. Caps aren't always reliable.

 

[Bart B.]

Has anyone ever checked their scope E and W adjustments for linear tracking? Thats when the horizontal reticle wire stays at the same place in elevation from stop to stop on the windage knob. Or the vertical one staying in the same place in windage from stop to stop in elevation.

Is one doesn't, the wire is not parallel to the other's adjustment flat.

 

[mikecr]

A lot of times a scope's reticle is plumb to nothing,, and it doesn't matter if you're dialing anyway.
Hell, in this case, you don't even need a reticle, but a simple point of aim (like a dot).

Anyway, if your dialing and hitting left off of plumb, you adjust the physical level leftward(counter-clockwise), so that you'd turn the gun clockwise(rightward) to regain a level for shooting more plumb.

 

[Texas10]

I had a question about this very issue recently and one member suggested setting up the scope reticle to plumb by hanging a plumb line on the wall and aligning both scope reticle and sighting down the barrel bore too so that the plumb string appears to be centered in the bore. This sets the barrel and scope in the same vertical plane. If turning the vertical turret up causes it to drift off vertical, then the issue is probably within the scope.

 

[Richard Coody]

it is easy to use a plumb bob and get the reticle level but much more difficult to level the rifle itself. plumb scope on a canted rifle?

easy check. tall target with a plumb line. max and minimum elevation does the scope track true? now is it a canted rifle or is the scope not aligned plumb.