Vortex Turrets Not Tracking Accurately

[trumperman]

Here is the scoop guys. The reason this happens is because a scopes erector tube is round and it sits in a round tube. This is perfectly normal and happens in just about every scope out there that a tactical long range shooter including pretty much all the scopes commonly discussed on this forum. The only way to stop this from happening is to severely impede the overall travel of the scope.

In the end it just comes down to basic geometry. A circle(erector tube with size being around .800") in-cased in a larger circle(scope tube with I.D. about 1.000") can move freely inside that circle. In order for the smaller circle(erector tube) to move the shape of a square it would need to be restricted. Which this is possible to do ,but in the process you would give up a large amount of real estate in the larger circle(scope tube) and end up not having the amount of elevation that we shooters demand. Just picture a square(proportional to smaller circle) inside the larger circle(scope tube) and you will see just how much you will give up.
As I stated earlier this is very common and the reason that it generally is never brought up is- very seldom do we find our selves dialing even remotely close to the amount of windage travel that is available in most scopes.

I hope I have explained this in a simple enough fashion.

 

[gohring3006]

Here is the scoop guys. The reason this happens is because a scopes erector tube is round and it sits in a round tube. This is perfectly normal and happens in just about every scope out there that a tactical long range shooter including pretty much all the scopes commonly discussed on this forum. The only way to stop this from happening is to severely impede the overall travel of the scope.

In the end it just comes down to basic geometry. A circle(erector tube with size being around .800") in-cased in a larger circle(scope tube with I.D. about 1.000") can move freely inside that circle. In order for the smaller circle(erector tube) to move the shape of a square it would need to be restricted. Which this is possible to do ,but in the process you would give up a large amount of real estate in the larger circle(scope tube) and end up not having the amount of elevation that we shooters demand. Just picture a square(proportional to smaller circle) inside the larger circle(scope tube) and you will see just how much you will give up.
As I stated earlier this is very common and the reason that it generally is never brought up is- very seldom do we find our selves dialing even remotely close to the amount of windage travel that is available in most scopes.

I hope I have explained this in a simple enough fashion.

Nope, it explains nothing to me as to why his turrets are not trued to 1.047" Moa. His problem is common, especially in that particular scopes price point.

I will add, a scope with upto 3% error is common and easily trued up with the proper ballistic calculator.

I would like to ask. Does the OPs turrets dial 1/4" at 100 yards or 1/4 Moa at 100?

 

[Barrelnut]

Here is the scoop guys. The reason this happens is because a scopes erector tube is round and it sits in a round tube. This is perfectly normal and happens in just about every scope out there that a tactical long range shooter including pretty much all the scopes commonly discussed on this forum. The only way to stop this from happening is to severely impede the overall travel of the scope.

In the end it just comes down to basic geometry. A circle(erector tube with size being around .800") in-cased in a larger circle(scope tube with I.D. about 1.000") can move freely inside that circle. In order for the smaller circle(erector tube) to move the shape of a square it would need to be restricted. Which this is possible to do ,but in the process you would give up a large amount of real estate in the larger circle(scope tube) and end up not having the amount of elevation that we shooters demand. Just picture a square(proportional to smaller circle) inside the larger circle(scope tube) and you will see just how much you will give up.
As I stated earlier this is very common and the reason that it generally is never brought up is- very seldom do we find our selves dialing even remotely close to the amount of windage travel that is available in most scopes.

I hope I have explained this in a simple enough fashion.

Understand what you are talking about, but don't think it fits the OP's situation. He is not trying to shoot a box test. OP, seems to have a problem with vertical dialing without even dialing much windage. Hope that's his issue anyway.

 

[Barrelnut]

Ran the OP's numbers and if I did the math right. The scope has an 11.42% dialing error. It is the exact same error for vertical and windage. This is a huge dialing error.

I happen to have figured the dialing error on a Vortex PST 6-24x50 scope I have. I figured it using 24 MOA at 100 yards with a tall target test. The dialing error on my scope is only .98%

Op's rifle seems to be accurate enough at 6 inside of 3/4". The scope is 2.87" high at 24 MOA at 100 yards. That's not good. Personally, I don't think parallax adjustment is gonna fix anything.

 

[Reload10]

Scope clearly indicates 1/4 MOA.

I'm going to test it again and set parallax as best as I can. Most likely will end up selling it though, ordered a NXS 5.5-22x50 MOAR-T today.

 

[ShtrRdy]

You won't be disappointed with the Nightforce.

 

[Reload10]

Here's an update today:

Went to my lower pasture range and double checked the distance from the tip of my bench to the target. 100' steel tape pulled 3x read 299' 9" to the bench. Sig Kilo read 99.9 yards to 100.0 depending if I was on the paper, or the Styrofoam backing . I don't think I can get closer to 100 yards.

Posted up a tall target I made that is 25 MOA in 5 MOA hashes. I spent way too much time trying to eliminate parallax and got it as close as humanly possible with an up and down, and side to side head movement without touching the rifle or bench. Parallax Dial read ~80 yards?

I started at the top (25 MOA), dialed the scope up (reticle down on target) in 5 MOA increments. Overall, when I got to 25 MOA dialed, I was ~26.0-26.25. I dialed back down on the scope and the reticle landed right back at initial location. I did this twice, and each time it was 26 ish MOA, but return to zero was very good!

The scope was not within Vortex tolerance of 1% (out of 100 clicks, should be within 1 click of actual). I was over 4 clicks off at minimum out of 100.

SO...I'll send it in and see what happens.

 

[Crews]

"But you can't beat the warranty!"

Can't tell you how many times I've heard that after another one of the masses purchases a Vortex. It's one of the cleverest marketing schemes I've ever seen

 

[Snowbird]

Here's an update today:


SO...I'll send it in and see what happens.

any updates on how the process went? i'm in the same boat with my pst.

 

[Reload10]

Send it in and they'll take care of you.

 

[Snowbird]

Send it in and they'll take care of you.

so they repaired or replaced it timely and to your satisfaction? i have many vortex scopes but never attempted to use the warranty.

 

[Creedmoor shooter]

so they repaired or replaced it timely and to your satisfaction? i have many vortex scopes but never attempted to use the warranty.

I had a gen 1 pst that had been overtighten on the tube and it did something on the inside so when I looked through the scope it looked like pepper on the objective. I sent it in and they had it back to me in less than 2 weeks no questions asked.

 

[Gwine]

I know it's small potatoes, but I stepped on a turret cap and bent the threads. Less than a week after I emailed them I had a new cap for my scope.

 

[DartonJager]

I agree, best to measure it with a tape.

How do you do this? Guessing a 100' tape 3x? Am thinking it will take some effort and help to keep the measurement straight and accurate, I'd be concerned about allot of distortion induced inaccuracy form the tape bending could occur. Measuring 300 feet with a maximum of 1" accuracy is no easy feet. No pun intended.