Scope Not Level With My Action

[Triple BB]

Wondering if anyone has run into this. I mount my scope and use one of those small levels that fits in the action and then sit a bubble level on the turret of my NXS. I get it so the bubbles match perfect. After shooting it at distance I can tell it's canted. I do a ladder test and confirm it's off.
So I get the gun set up and verify the action is perfectly level. I hang a plumb bob 80 yards away and sure enough its canted at about 11:57. With the bubble on the turret the bubble is touching the line while it's perfectly centered on the action. I checked both bubble levels on two quality levels I use for construction and both were on. I should've gone to the plumb bob to begin with. Is it unusual for a turret on a quality scope to not match the action.

 

[Remmy700]

I have seen it more often than not that the base its what is slightly off from action centerline. This is way more frequent on rem and savage actions than on the high end actions. Rarely ever see this issue with one piece actions. A method I have used for years is simply using feeler gauges between flat on bottom of scope and top of scope rail. After that I will just check on tall target with a rail mounted level installed to ensure its good. I have almost all one piece actions now so don't really see that scope base issue any longer. I am sure some others will chime in. Each scope manufacturers have their own specs for how canted the scope reticle can be and some of them are a little more generous that I would have thought also.

 

[Mikecr]

What matters if you're holding off is reticle plumb.
What matters if you're dialing is elevation adjustment plumb.
The stock, bedding, action, base, rings, turret, never matter at all for this.

The best level for this is mounted closest to what matters, and that's the 'Scoplevel'.
It's mounted on the scope body and once set to that scope you can move the scope from gun to gun and plumb is always plumb, regardless of gun/build, -because what's level is the scope itself (either reticle or internal adjustment).

 

[762x51]

I have seen it more often than not that the base its what is slightly off from action centerline. This is way more frequent on rem and savage actions than on the high end actions. Rarely ever see this issue with one piece actions. A method I have used for years is simply using feeler gauges between flat on bottom of scope and top of scope rail. After that I will just check on tall target with a rail mounted level installed to ensure its good. I have almost all one piece actions now so don't really see that scope base issue any longer. I am sure some others will chime in. Each scope manufacturers have their own specs for how canted the scope reticle can be and some of them are a little more generous that I would have thought also.

this is what i was going to suggest. this is how i do all my rifles now. i tried the wheeler kit where you use one level on the action and the other on the elevation turret and it always ended up very off. like i could have done a better job doing it by eye than using the levels. i do it on my AR's and my bolt guns. even my .17 hmr

 

[nvschütze]

You're getting a bit of roll when you tighten-down the upper rings. I've had this happen, too. I've wondered if the turret on the top of the scope is perfectly level. All we can do is assume that it is unless we can really see that it's not. I use the Wheeler Engineering Professional Reticle Leveling System-- the same one that's used at the big Scheels in Sparks, NV. If I tighten the ring screws just right in an alternating & opposite sequence, I can usually get the rings tight and not roll the reticle. Usually-- but not every time. If the scope rolls, I have to start over and pre-load a bit of roll into where I set the scope before beginning to tighten the ring screws. It can be very frustrating. The human eye can resolve 1/80 of an inch at 12 inches. It's a good possibility that you'll see your reticle being tilted if it truly is. If it is, you'll see it on your targets...

 

[Frog4aday]

nvschutze,
I'm so glad you wrote this! Saw the same problem recently as I was tightening the scope rings on a .22 Hornet. Got everything perfectly level, then started to snug the ring screws down and danged if that scope didn't want to 'roll' to whichever side I was tightening. As you said, I had to loosen, rotate, and try again, being as careful as I could to tighten each side equally so it all stayed level. Just a big PIA, but eventually it is 'done'. Then you don't ever want to take it off again, ha!

 

[Deleted member 103481]

The best thing about ARC rings is the single bolt at the top so you don't have to worry about scopes rolling.

 

[Barrelnut]

Scopes don't seem to roll with Leupold PRW2 rings either. I've put them on three rifles and had no scope roll issues. I believe it is because the ring screws are below the midpoint of the side of the scope.

 

[762x51]

TPS makes their TSR model rings that are supposed to eliminate the scope roll as well. you tighten the left side completely, then tighten down the other side. i've got them on my 700. they kind of look like badger rings, but cheaper. i paid $80 for them about 5-6 years ago and now they're $105 at midway.

 

[nvschütze]

Then you don't ever want to take it off again. . .

You've got that right! I use Picatinny rails on as many of my beloved possessions as I can. Once it's on and level, the rings come off with the scope-- never just the scope removed and the rings staying attached. It can be expensive, but it bugs the hellsinki out of me to have to fight the scope rolling over when I have to mount it again onto another beloved possession...

 

[Hand Skills]

Wondering if anyone has run into this... ...I should've gone to the plumb bob to begin with. Is it unusual for a turret on a quality scope to not match the action.

Yes, as others have mentioned, cause could be the scope rolling in the rings. It could also be the reticle isn't 100% aligned to the erectors in the scope itself. No alignment is perfect, but some manufacturers have higher tolerances than others in this regard. I know of a popular American brand, for example, for whom +/-1.5° is accebtable. I haven't owned a lot of expensive scopes, but I believe better QC and tighter tolerances contribute to the premium price we pay for high grade optics.

The easiest way to test this is to use the reticle to holdover shoot a tall target. Then use turrets to shoot the same tall target. If both methods result in the same POI, you're good.

The best thing about ARC rings is the single bolt at the top so you don't have to worry about scopes rolling.

Always wanted to try some. I like that the torque spec is the same on both screws also. Simplicity through engineering!

... Once it's on and level, the rings come off with the scope-- never just the scope removed and the rings staying attached. It can be expensive, but it bugs the hellsinki out of me to have to fight the scope rolling over when I have to mount it again onto another beloved possession...

I feel you there. Im the process of transitioning to this way of thinking.

Agreed @Remmy700 I would never put a '2 piece' set of bases on an open receiver (rem700 or win M70 for example) again. Bedded rails from now on, or a quality direct mount at the very least. There should be no reason for ring burn, nor should one need to lap rings.

I preferr scope mounted levels because they are easy to calibrate. Levels in bases and rings don't make sense to me because not only are they harder to see from behind the scope, they are a lot trickier to dial in. No guarantee that those bubbles are perfectly calibrated either... When attaching a level to a scope it's still fussy, but a lot easier to get the bubble centered while the reticle is plumb.

Oh snap, does ARC made a bubble level?!

 

[Remmy700]

Arc mounts have one built in don't know about two piece rings set!

 

[YZ-80]

I use the Wheeler kit as well but it is a bit persnickety as others have alluded to. I agree that the top of the turret knob is not always true, and if you are lucky enough to have a flat spot on a milled action/receiver to attach the other level, there's no garuntee that this is true either. The other thing that can drive you nuts is that even if you do have the reticle plumb, you can end up second guessing yourself when you shoulder the rifle on your cheek weld because it will often still look canted and you end up chasing it all over the place. Scope cant is another one of those annoying things in life. It's right up there with hose memory in my opinion.

 

[Remmy700]

Yeah scope cant or not cant is often amplified my the cheek weld on that particular rifle whether it's steep or very round. Often times the way u get behind rifle just looking can make the perception of cant. Tall target test with a rail mounted level is the only way to really see it.