Vortex Viper PST zero stop is inconsistent

[Whiterabbit]

yes it overshoots. Tell us if it overshoots the same every time.

I need to qualify "variable". At home or between shots, the zero stop is quite sufficiently repeatable. It's under recoil (338 lapua, and I often shoot with no muzzle brake) that I notice the zero stop position significantly shifts.

So this isn't repeatable at home. Only on the firing line.

also a Q for those that used shims... is it because you are reloading and know the performance already? i'm not there yet and will be using either priv partizan 168gr or black hills 168gr or 175 gr. so wondering if it makes sense to even have a zero stop for me vs. just noting where it is just like everyone else w/o a zero stop i figure.

I reload for financial prudence, but it wouldn't matter if I reloaded or only shot factory ammo. I'm a "one load, one rifle" kind of guy and follow this even with guns I do not reload for. So when I set my 100 yard zero and a zero stop, it's not meant to change. Not until I can't buy nosler E-tips. anymore.

We do not know the performance before hand, we add the shims after sighting in.

I wanted a 100 yard zero, so I had NO shims in when I started, and zeroed at 100 yards. Then I pulled the cap THEN I added the shims. Then put the cap back on rotated to zero, all without making ANY adjustments. Then I turned away a partial rotation, then rotated down, passing my 100 yard zero, till the dial stopped. That confirmed that I didn't go 15 MOA past my 100 yard zero.

[M1Kev]

Here is what vortex told me when I called before I put in the shims. 1) zero rifle at desired range. 2) remove the elevation cap straight up. 3) install the shims, there should be a gap. Do not fill up the space, the last one should not be tight. 4) reinstall the cap so the 0 is lined up with the opening.

When returning to zero, you will go past. Turn the knob back until it stops and then rotate forward until 0 is lined up. Zero stop is inconsistent where it stops, but will always be on the original rotation (i.e. the next 0 forward will be your 0). The stop is not meant to be the end, it is meant to stop you from rotating past the revolution where your 0 was set. Metal shims expand and contract with temp changes, they are not meant to provide a consistent stop at the same exact number, they provide a consistent stop at the same revolution of the turret.

[HK Dave]

Without reading anything written here... I will explain simply...

Because it's NOT a REAL ZERO STOP.

Using shims to create a zero stop by tension does not equal a zero stop. Only close to it.

Real Zero Stops start at around the $1500 mark for riflescopes.

[Whiterabbit]

Without reading anything written here... I will explain simply...

Because it's NOT a REAL ZERO STOP.

Using shims to create a zero stop by tension does not equal a zero stop. Only close to it.

Real Zero Stops start at around the $1500 mark for riflescopes.

you didn't even read the OP.

[HK Dave]

Just read the OP and the posts that followed. My response is the same. It's not a real zero stop or rather a hard stop. It uses a tension system derived from shims that change consistency depending oh how it rotates or where one shim is relative to another.

It will always be inconsistent.

Real zero stops start at $1500.

From what I remember of my PST, it wasn't THAT inconsistent though. I remember it being off by 1 click or 2. Call Vortex, bet they'll take good care of you.

[HK Dave]

I love how these are the differences between $1200 glass and $3000 glass. Things like that should be perfect at any price point.

Hmm I don't think this is really a fair statement. Vortex went to a different level, trying to stuff everything people wanted into a sub $1K scope. They had to make compromises to make it happen.

At under $1K it "can't" be perfect when its chock full of so many cool options simply because Vortex would lose money on each scope. :P

Now at $3K-4K, it damn well better be perfect out the box without me having to send it back because you're paying for all the top end components.

Case in point, bought a S&B PMII 5-25x56mm... ships to my house and the elevation turret clicks are mushy when compared to the windage and def mushy when compared to my Premiers.

Now I have to ship the POS to the factory to get the detent properly set or repaired... shipping will cost something like $100+ because of insurance.

I love Vortex because if that had happened... even with a sub $1K scope, they'd send me a UPS label to have the scope shipped on their dime.

Gotta love that.

But back to the point... if a Vortex Viper had some inconsistencies, i'd be happy about it and live with it.... although the OPs situation doesn't sound normal if it's inconsistent by more than a few clicks.

[Darklyte27]

Shims go forward backward forward backward. havent had any problem on mine.

http://www.vortexoptics.com/uploads/web_manual_rfl_viper-pst-14st-12a.pdf

[Whiterabbit]

yep did that.

Just checked it tonight. It's accurate to within a couple clicks. Then under simulated recoil, the new stop point can shift a lot. From the 1moa mark to passing the zero and hitting the 9 moa mark that much farther.

Try it. back the dial off one full rotation, simulate recoil (or shoot a round at the range) and see where it returns.

Without that recoil event it stops within a click or two to the same spot every time. With it, who knows where it stops!

[Iloveguns]

So why does it go all the way back to the 1 MOA mark? If you zeroed your knobs then to have it go back 8 MOA means there should be enough room for at least one more shim.

[Whiterabbit]

Because if I put one more shim in there, after it "readjusts" its sero pointunder recoil, I cant get it even back to the original zero.

Remember, the zero stop on my scope shifts absolute stopping point by SEVERAL MOA every time the rifle is fired, if the adjustment is not on the zero (as in, long range shooting). So if I put one more shim in there and it stops, say, 5 MOA past zero, the next time I shoot, the zero stop might not return to 5 MOA past zero but rather stop 2 MOA BEFORE reaching zero.

That's the problem.

[Iloveguns]

Send it back in. Vortex CS is top notch. Should get a new one or yours fixed in 2 weeks.

[ExtremeX]

OP... I totally forgot about this thread them remembered about it after I moved my 1-4x Vortex PST scope to my 10/22 and had to reset the shim zero stop.

What you experienced is normal... since I just experienced the same thing couple weeks ago, and I forgot what I did to get it working right in the first place when I originally set it up.

You know how Vortex instructions says not to force shims into the thing... well that's only partially true.

Tip:
After getting your zero install as many shims as you can fit into it....
Re-install turret cap, make sure you don't loose ur zero, then ride the knob up and down, this will help settle the shims (I was able to overshoot my zero by almost one full rev)
Remove turret cap and install more ships.
Re-install turret cap, and repeat.
Remove turret cap and install more ships if needed.
Repeat process until you cant fit any more shims...

By the time I got to the last shim I could fit... it was pretty snug (be sure not to bend a shim)

After doing this... I get a pretty hard stop around 2 MOA past my zero... and it stays like that.

I can see why you were complaining, but getting the zero stop setup correctly takes a little work, but it works well once you get it done.

[Whiterabbit]

I was thinking about cutting my own zero stop out of brass round stock.

[ExtremeX]

If you have a lathe and can machine your own with accuracy you would be in pretty good shape.

If you install the shims like I mentioned you get a very reliable and repeatable zero stop.

[Whiterabbit]

let me know if your shim stack "de-settles" under recoil, preventing you from returning to your original zero. That's exactly what happened to me.

Your method was the FIRST thing I did, months and months ago.