Vortex Viper PST zero stop is inconsistent

[Whiterabbit]

Hi Guys,

Any of you notice the zero stop inconsistent on your PST? I set mine so that it stops at, say, 8 MOA adjustment on the way around, and when I re-zero, it'll stop at 10, 6, 4, etc. Wild.

This isnt normally a problem, but it does result in a lack of trust on the adjustment.

So now, I come back from the range and re-set the zero having "lost" mentally how many times I've rotated the turret. It stops at 1 MOA. So now I am left wondering, did the shims shift thick, so I need to re-set the shims to get that last MOA to re-zero? or did they settle SO much, that I've gone nearly all the way round again and need to add another shim?

Now I have to go back out to the range and fire a shot to confirm.

This is not a good way to solidify reliability!

Am I the only one who notices this? are my shims simply not installed as effectively as I could? Who else has dealt with this? Is there a solution? Is there a way I can at least have it reset within 1-2 MOA every time?

Thanks guys,

-S

[Iloveguns]

Not sure but it sounds like you don't have enough shims in there. Where they bent at all when you installed them?

[Whiterabbit]

No, they were/are all flat. Do you have experience with the PST zero stop? Specifically, owning a PST, installing, AND using the zero stop? Or are you making an educated brainstorm suggestion?

Thanks,

-S

[Iloveguns]

I do.

[Whiterabbit]

have you ever experienced this? what kind of variance do you see on your PST?

[Iloveguns]

I have not had any variances. Its not a mechanical Zero Stop so it should not change once its set correctly. Which leads me to think for some reason you dont have enough shims. But I could be wrong.

[dieselpower]

From a guy who doesnt own a PST, nor do I shoot extreme ranges... Walk me through exactly what you are seeing.

Are you re-confirming your zero, or do you have to re-zero, because from what it sounds like to me you are saying your zero is shifting wildly.

When you think it should come back and stop at 8, and it goes to 10, did you confirm it was zeroed then? Or did the shim move and you were 2 off?

Either your zero is shifting or the shims are. The only way to tell which is happening is making sure you are not miscounting and also to verify if the zero has shifted. A hard stop is a hard stop...if you can click passed it...its not a hard stop...LOL

big time tag for the memory banks...

[joelogic]

I was reading the manual and it said going past zero is normal. The CRS is not a hard stop.

[Iloveguns]

His problem is not that he is going past Zero. His problem is that he goes past zero at different marks each time. Its not at the same spot every time. But this time its right at 1 MOA which causes him not know if he is low 11 MOA or High 1MOA.

[dieselpower]

oic....

[Whiterabbit]

I have not had any variances. Its not a mechanical Zero Stop so it should not change once its set correctly. Which leads me to think for some reason you dont have enough shims. But I could be wrong.

First time around, I thought so too. So I put an extra shim in there when it was especially low. Then the pendulum swung the other way and I couldn't index to the original zero and had to pull the shim back out.

So you haven't had any variances, does that mean in your case that you stop at the EXACT same spot every time? accurate to the 1/4 moa?

[ExtremeX]

I was reading the manual and it said going past zero is normal. The CRS is not a hard stop.

+1

The shims there so you don’t overshoot by another full rotation.

Mine goes over… but I know it doesn’t go past that, and just zero it on the mark.

[Whiterabbit]

But yours clearly is not consistent ether ExtremeX, is it.

[ExtremeX]

I mistyped earlier by how much… Ill check that later when I get home. It’s not by much… There is no way I could rotate the knob by one full turn.

The scope is functioning correctly… that’s one of the downsides with a shim stop vs the zero stop. It was part of Vortex value engineering when the scope was designed.

I have two PST scopes and both of them act the same way.

If you want less travel, add another shim.

[Whiterabbit]

you miss my question. It's not that it passes through zero, its that it does not stop at the same point. You originally said 2-3moa past. Doesnt matter if it is 2-3 MOA past, 5-6 MOA past, or 9-10 MOA past, you are implying your variance is 1moa. My point is that on my scope it is apparently in the neighborhood of 2-10 MOA past, meaning a variance of 8+ MOA or more. That's not very good at all.

If it were 4-7 MOA past (3moa variance) then it would be no problem. Just put enough shims in there to make sure within limits its never close to one full rotation (nowhere near the zero point).

It's just that on my scope it stops at such a wide range that either I risk not being able to return to zero, or it overshoots by nearly one full rotation (sometimes). It's just not consistent.

I assume its operator error (didn't put the shims in properly?) but without positive confirmation of the root cause, I can't apply a correction. Part of finding the root cause is finding out if anyone else has the issue. If not, then what are you guys doing that I am not?

I'll bet your scope doesn't stop at the same spot exactly every time you cycle it. Iloveguns says he has no variance, I asked for a confirmation of that. He'll get back to me when he can. But since you already said before editing that you were 2-3 MOA past, I'll bet you have variance too, even if the range is not as severe as mine.

Ultimately, I'm trying to get my variance tighter also. Adding or subtracing shims has not helped variance, merely where the limits fall.