Rifle Scopes S&B Problem?

[lvmike]

Anyone ever seen a 5-25 S&B do anything like this? It has a gen2xr if that matters...


Its kind of hard to see in the pic but the edge of the scope at the top is somewhat blurry and at around 10 to 2o clock it starts to shadow a bit of what should be visible. This happens at around 17x+.. Basically, the picture looks almost exactly like it does with your actual eye. I have shot it a little so far and it seems to track and hold zero for the 70 rounds its been used so far. If it doesn't hurt function I may not worry about it but I havent used it enough to really know yet.

So, bent tube? Normal for a premier modified S&B?

 

[Wheres-Waldo]

Re: S&B Problem?

I have the same GenII 5-25...mine is clearer than Hitlers intentions.

Its only doing this at the specified 17x?

 

[lvmike]

Re: S&B Problem?

Nope, it starts at 17x and pic is at 25x. It is as clear as my premier 5-25 otherwise.

 

[dcjs]

Re: S&B Problem?

My guess is that you have this scope sitting on a strongly canted base, correct?

What you are seeing is a consequence of the erector being close to the edge of the travel range (down in this case, opposite if up). The erector is "looking" at the edge of the image created by the objective system. This effect can be observed to varying degrees with pretty much all scopes that have a large adjustment range that I have seen so far. Some models only show a hint of it, but I've seen a well-known scope model actually lose 2 mils of FOV at one edge due to this.

If you crank in some elevation, it'll go away.

 

[lvmike]

Re: S&B Problem?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: David S.</div><div class="ubbcode-body">My guess is that you have this scope sitting on a strongly canted base, correct?

What you are seeing is a consequence of the erector being close to the edge of the travel range (down in this case, opposite if up). The erector is "looking" at the edge of the image created by the objective system. This effect can be observed to varying degrees with pretty much all scopes that have a large adjustment range that I have seen so far. Some models only show a hint of it, but I've seen a well-known scope model actually lose 2 mils of FOV at one edge due to this.

If you crank in some elevation, it'll go away. </div></div>

Excellent call, its in a AI 45moa base (made for this model S&B) and with 5mils up its completely gone. Havent gotten the rifle (.243) out far enough yet to get more then 5 mils on the knob. Into the second turn it shows up at the same way on the bottom. Had never seen this before but now I know its not a defect it doesnt bother me.

thanks

 

[Hellbender]

Re: S&B Problem?

Check your adjustments carefully, my 5-25, when it gets close to elevation extremes (like dialing a 15 FOOT shot) will start adding windage.

It's repeatable, but you still need to know, as it will give you fits trying to figure it out.

I'd get a lesser MOA base, unless you need it for extreme ranges and don't plan on shooting closer.

 

[psinclair]

Re: S&B Problem?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: David S.</div><div class="ubbcode-body">My guess is that you have this scope sitting on a strongly canted base, correct?

What you are seeing is a consequence of the erector being close to the edge of the travel range (down in this case, opposite if up). The erector is "looking" at the edge of the image created by the objective system. This effect can be observed to varying degrees with pretty much all scopes that have a large adjustment range that I have seen so far. Some models only show a hint of it, but I've seen a well-known scope model actually lose 2 mils of FOV at one edge due to this.

If you crank in some elevation, it'll go away. </div></div>

Bingo!

 

[Notso]

Re: S&B Problem?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LVMIKE</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: David S.</div><div class="ubbcode-body">My guess is that you have this scope sitting on a strongly canted base, correct?

What you are seeing is a consequence of the erector being close to the edge of the travel range (down in this case, opposite if up). The erector is "looking" at the edge of the image created by the objective system. This effect can be observed to varying degrees with pretty much all scopes that have a large adjustment range that I have seen so far. Some models only show a hint of it, but I've seen a well-known scope model actually lose 2 mils of FOV at one edge due to this.

If you crank in some elevation, it'll go away. </div></div>

Excellent call, its in a AI 45moa base (made for this model S&B) and with 5mils up its completely gone. Havent gotten the rifle (.243) out far enough yet to get more then 5 mils on the knob. Into the second turn it shows up at the same way on the bottom. Had never seen this before but now I know its not a defect it doesnt bother me.

thanks </div></div>

I can't imagine any use for a 45 MOA base that you couldn't shoot. Your S&B has tons of elevation anyway and the .243 is probably never going to need that much to begin with. Maybe get something more in the 20-30 MOA and never worry about that issue again.

 

[dcjs]

Re: S&B Problem?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hellbender</div><div class="ubbcode-body">Check your adjustments carefully, my 5-25, when it gets close to elevation extremes (like dialing a 15 FOOT shot) will start adding windage.

It's repeatable, but you still need to know, as it will give you fits trying to figure it out.

I'd get a lesser MOA base, unless you need it for extreme ranges and don't plan on shooting closer. </div></div>
That does not sound healthy. Either your scope hase some individual problem or the adjustment range isn't rectangular by design so you have windage and elevation colliding at the extremes of the travel range. Either way, you shouldn't be dialing into the "danger zone" if you don't want to risk erratic results.

 

[lvmike]

Re: S&B Problem?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Notso</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: LVMIKE</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: David S.</div><div class="ubbcode-body">My guess is that you have this scope sitting on a strongly canted base, correct?

What you are seeing is a consequence of the erector being close to the edge of the travel range (down in this case, opposite if up). The erector is "looking" at the edge of the image created by the objective system. This effect can be observed to varying degrees with pretty much all scopes that have a large adjustment range that I have seen so far. Some models only show a hint of it, but I've seen a well-known scope model actually lose 2 mils of FOV at one edge due to this.

If you crank in some elevation, it'll go away. </div></div>

Excellent call, its in a AI 45moa base (made for this model S&B) and with 5mils up its completely gone. Havent gotten the rifle (.243) out far enough yet to get more then 5 mils on the knob. Into the second turn it shows up at the same way on the bottom. Had never seen this before but now I know its not a defect it doesnt bother me.

thanks </div></div>

I can't imagine any use for a 45 MOA base that you couldn't shoot. Your S&B has tons of elevation anyway and the .243 is probably never going to need that much to begin with. Maybe get something more in the 20-30 MOA and never worry about that issue again. </div></div>

The issue really isn't an issue though. I can still tell when my eye is centered in the scope fine. Going to put it through some actual tracking tests (especially large positive elevation tests) and verify it behaves ok and then forget about it.

 

[Hellbender]

Re: S&B Problem?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: David S.</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hellbender</div><div class="ubbcode-body">Check your adjustments carefully, my 5-25, when it gets close to elevation extremes (like dialing a 15 FOOT shot) will start adding windage.

It's repeatable, but you still need to know, as it will give you fits trying to figure it out.

I'd get a lesser MOA base, unless you need it for extreme ranges and don't plan on shooting closer. </div></div>
That does not sound healthy. Either your scope hase some individual problem or the adjustment range isn't rectangular by design so you have windage and elevation colliding at the extremes of the travel range. Either way, you shouldn't be dialing into the "danger zone" if you don't want to risk erratic results. </div></div>

It's a round tube moving in a round tube, if the inner tube runs out of adjustment at a "corner" the "corner" is round, not square; so may be shoved a little one way or another.

Mine is an extreme example on a AR (very high mount) and only happens at the very limit of travel. It is repeatable, so no problem.