Rifle Scopes How to verify a canted reticle?

[glock24]

I have a Sightron SIII I'm trying to mount in pair of TPS rings on a USO Picatinny base. No matter what I do, the damn reticle just doesn't look straight.

I'm using the feeler gauge method to level the scope, and this isn't my first rodeo. Still, when the rifle is rotated level via a fixed, USO, rail-mounted bubble level, the reticle sure looks canted to my eyes. The vertical cross-hair doesn't look truly vertical, and it doesn't seem to extend straight into the receiver, bisecting it. This visual description is what I'm used to seeing with my other scope's reticles when the rifle is leveled.

Before I cry foul and send it back to Sightron, does anyone have any full-proof methods of verifying reticle cant?

I've verified the USO bubble level by placing a second level on the rail. They both agree, however that doesn't mean that the rail isn't crooked to the receiver. Unfortunately I don't have a good, flat surface on the receiver itself to verify its level against the rail.

I've thought about using the plumb bob method, but that only works if I know the rifle is level. Unfortunately the only way I can level the rifle is by using the flat surface of the Picatinny rail, and this is potentially suspect.

Has anyone tried removing a scope, and placing the flat bottom of the turret housing on a known level surface? If I did this, and then viewed a plumb bob while the scope was resting on this level surface, would that confirm reticle cant?

Should I try mounting another scope on this rifle and see if I get the same results? Would that rule out the rail as the problem?

I'm down to blaming the scope, or suspecting the rail is crooked. Anyone know of a good way to rule out one of these two variables? I would at least like to have done my homework before I send my scope back.

Thanks

 

[Graham]

Re: How to verify a canted reticle?

You don't need a level surface if you have a swivel bi-pod.

Pull the bolt. Level the rifle at the action rails. Level the scope. Level the elevation turret. If the reticle appears to be canted, it is.

Because the real problem isn't the rifle not being level, it's the reticle not being perpendicular to the turret adjustments.

It would take a lot to go wrong for the base to be uniformly canted to one side.

 

[glock24]

Re: How to verify a canted reticle?

I hear ya man, unfortunately I can't seem to get a bubble level across anything square on the receiver itself. The action rails sit below the ejection port, and I can't reach them with my current bubble levels. I'm using that Wheeler Engineering gizmo that comes with a pair of tiny torpedo tubes.

I'm now thinking about holding the scope upside-down and placing a bubble level across the flat bottom of the turret assembly. I'm thinking this only because there isn't a flat surface on the elevation turret either, even when I remove the cap!

 

[Graham]

Re: How to verify a canted reticle?

PM inbound.

 

[sobrbiker883]

Re: How to verify a canted reticle?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: glock24</div><div class="ubbcode-body">Has anyone tried removing a scope, and placing the flat bottom of the turret housing on a known level surface? If I did this, and then viewed a plumb bob while the scope was resting on this level surface, would that confirm reticle cant?

</div></div>

Never tried that, but it sounds like a plausible way to verify the reticle beong squared to the adjustment assembly.

On another note, while doing the plumb bob thing, with the reticle parallel to the plumb line, run the elevation up and see if the crosshairs veer off the line-if so, the reticle isn't square with the erector.

 

[glock24]

Re: How to verify a canted reticle?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">
On another note, while doing the plumb bob thing, with the reticle parallel to the plumb line, run the elevation up and see if the crosshairs veer off the line-if so, the reticle isn't square with the erector. </div></div>

That's a good idea.

Thanks

 

[BCP]

Re: How to verify a canted reticle?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">PM inbound. </div></div>

Can I have a PM too? I have a certain scope that's driving me nuts, almost looks like the horizontal part of the crosshair is cockeyed.

 

[The Mechanic]

Re: How to verify a canted reticle?

Level your USO level. Hang a string at 100 yards from a tree with a piece of split shot fishing weight near the top and at 36 inches down. Yellow string works well. Now align the reticle with the string and track your scope with the elevation turret and see if it tracks along the string or ends up off to one side or another. You can guess what results are good an bad.

 

[EricF517]

Re: How to verify a canted reticle?

I do something similar to the plumb bob method you guys are talking about. Since my target are a 4x4 sheet of ply, and I use builder's paper for floors as a covering, I take a level with me, sharpie marker, tape measure, and two 1" shoot n c's. First I make sure my scope is 100% zeroed. Then I use the level to draw a 4" level line up the paper. Place a dot near the bottom, measure up 36" and place the other dot. Shoot the bottom dot, and adjust elevation and shoot the second dot. If I am on the line with both shots then I am good.

 

[glock24]

Re: How to verify a canted reticle?

Thanks for all the input guys.

Graham offered to meet me at our local range and he spent some time with my rifle. After verifying the receiver and scope body where reasonably level, it took only a quick glance through the scope to see that the reticle was canted.

I'll give Sightron a call next week and see what kind of customer service they offer.

 

[Jackalope33B]

Re: How to verify a canted reticle?

Kudos to Graham for helping out a Hide member!
I do have a question. I see alot of guys are talking about using the plumb bob to verify your reticle is tracking. Lets say that your reticle is tracking up and down. Do you need to verify if it is tracking left to right or are you good to go once to verify that up and down if aligned?

 

[Graham]

Re: How to verify a canted reticle?

You've got to check the tracking for both elevation and windage, thus a 'box' test of some type through a meaningful adjustment range. Here we were concerned with how much windage he would get when he only dialed elevation. If memory serves, at 100m with 30 MOA dialed, the scope gave 35.25" of actual travel center-to-center with about 1 1/2" of POI change to the left (yet to be confirmed with a plumb).

 

[Casey Simpson]

Re: How to verify a canted reticle?

This one. Or the string but use a heavier weight so the air movement doesn't disturb it. Contrasting colors string/background.<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: EricF517</div><div class="ubbcode-body">I do something similar to the plumb bob method you guys are talking about. Since my target are a 4x4 sheet of ply, and I use builder's paper for floors as a covering, I take a level with me, sharpie marker, tape measure, and two 1" shoot n c's. First I make sure my scope is 100% zeroed. Then I use the level to draw a 4" level line up the paper. Place a dot near the bottom, measure up 36" and place the other dot. Shoot the bottom dot, and adjust elevation and shoot the second dot. If I am on the line with both shots then I am good. </div></div>

 

[Jackalope33B]

Re: How to verify a canted reticle?

Can you describe what the "box" test is?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">You've got to check the tracking for both elevation and windage, thus a 'box' test of some type through a meaningful adjustment range. Here we were concerned with how much windage he would get when he only dialed elevation. If memory serves, at 100m with 30 MOA dialed, the scope gave 35.25" of actual travel center-to-center with about 1 1/2" of POI change to the left (yet to be confirmed with a plumb). </div></div>

 

[tacshooter223]

Re: How to verify a canted reticle?

I think he is referring to when you get a target with the center dot and four on the top left, top right, bottom right and one in the bottom left. Start by shooting 3 bullets in the top left target. Adjust your scope by however much it may take to reach the top right target. Keep aiming at the top left. Shoot three more rounds. Then adjust the scope down until it should hit the bottom right target while still aiming at the top left. Then do the same for the bottom left target, still aiming at the top left. Finally when you move the scope back up you should be at the same you were zeroed at before. After shooting your last three rounds you should have six rounds in the top left and three in all the others if your scope is tracking correctly.