Rifle Scopes Reticle jump on FFP scopes?

[glock24]

I've seen this phenomenon on more than one less-expensive FFP scope (Falcon and Vortex);

Whenever the magnification ring changes direction (CW to CCW, or vice versa), just before the reticle starts growing (or shrinking) there is a little bounce or jump in the reticle. I've even been able to get the reticle to bounce repeatedly if I lightly torque the mag ring CW, then CCW, without even moving the ring. This happens at any power, but only when the ring changes direction.

What causes this? POI shift concerns? Will it get worse?

Thanks

 

[kepler314]

Re: Reticle jump on FFP scopes?

Does the image jump also, or is the reticle jumping relative to the image?

Is the jump a sideways or vertical shift, or does it suddenly get bigger or smaller (a zoom jump, in other words).

 

[sobrbiker883]

Re: Reticle jump on FFP scopes?

Call the retailer or manufacturer-I wouldn't dig it personally. Reticles that move any time I am not expecting them to do not make my confidence wax....

 

[glock24]

Re: Reticle jump on FFP scopes?

I guess "bounce" probably isn't the right word, as it is more of a shift.

When I turn the mag ring CW, the reticle shifts in a 4 o'clock to 10 o'clock direction. When I turn it CCW, the reticle shifts back from 10 to 4.

This shift is relative to the image, in other words the image moves in the same way also. I guess that's good, right?

Argh! I think I'll need to experiment with POI shifts before making any decisions. My first precision rifle class is in 3-weeks, and the scope is the 4-16x50mm Vortex PST. Heaven only knows when I'll get it back if I send it in right now.

 

[sobrbiker883]

Re: Reticle jump on FFP scopes?

I'd explain what's going on to Sam or Scott at Vortex, see if they can send a call tag and a replacement since you have a class coming up.....
Never hurts to try.

 

[glock24]

Re: Reticle jump on FFP scopes?

I hear ya, I just don't know if I want to scream foul just yet. I understand that it seems like a strange phenomenon, but it may also be completely normal. Wishful thinking?

I guess I was hoping someone had a definite answer either way. I'd feel better about exercising my warranty for a mechanical problem, not a mechanical curiosity.

 

[sobrbiker883]

Re: Reticle jump on FFP scopes?

If you're confident its not a problem, then it may not be.
Do you want that in the back of you mind during a class? If you miss what felt like a good shot are you gonna question your gear?

Just my experience, but a scope I have any lack of confidence in drives me nuts and affects my performance. Wouldn't be saying it if I hadn't experienced such firsthand.

 

[glock24]

Re: Reticle jump on FFP scopes?

I completely understand, and I tend to lean that way normally. That's why I'm hoping someone with experience in this matter can help clarify what I'm experiencing. My paranoia has helped to remove more perfectly zeroed scopes from my rifles than I care to admit!

I'll probably cave and see what Vortex says tomorrow!

Thanks for the insight.

 

[JL]

Re: Reticle jump on FFP scopes?

With FFP scopes, Its easily possible to move reticle+image by playing with ocular. When you look thru scope, and twist diopteria correction tube firmly up/down at the same time, reticle goes up and down WITH image.

So its not effecting zero any way, and happens with Zeiss Diavari as well.
If it would be SFP scope, I would be more worried because actual reticle is located inside ocular housing.

 

[Graham]

Re: Reticle jump on FFP scopes?

I have also seen it on very expensive scopes. Some individual FFP scopes do it more than others - even within the same brand. Place the objective on a table, illuminate the reticle, slowly change the magnification and observe whether or not the reticle itself moves as well as changes its size.

 

[Clay_James]

Re: Reticle jump on FFP scopes?

My 5.5-25x50 Falcon does it as well. I was really concerned at first but after some experimenting I determined the image moves with the reticle and it holds zero.

 

[338LM]

Re: Reticle jump on FFP scopes?

I have seen reticle jump on a couple S&B scopes.

 

[BFD711]

Re: Reticle jump on FFP scopes?

I've never seen this happen. Guess I should consider myself lucky despite having some high $ scopes.

 

[sobrbiker883]

Re: Reticle jump on FFP scopes?

I don't see it on the Falcon 4-14 I just traded into, and I've never seen it those FFP scopes from California. Never noticed it on a Premier.
On one of the IOR 3-18's I've had the reticle moved when the adjustment turrets were torqued (canted temporarily while pressure was applied to turrets, then went back when released). It was on a flight for Colorado as soon as I could get it there.

Again, I'd ask the guys that designed the scope if a shift while turning the power ring is to expected. If they say its inherent to the design, cool.

 

[azimutha]

Re: Reticle jump on FFP scopes?

If you want confidence wax, you're going to need to pay for it. Get a better scope.<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sobrbiker883</div><div class="ubbcode-body">Reticles that move any time I am not expecting them to do not make my confidence wax.... </div></div>

 

[JL]

Re: Reticle jump on FFP scopes?

F.e. in (all?) german scopes, diopteria correction is basically done same way: O-rings seal rotating, adjustable ocular part. Since there has to be seals, and rubber is flexible, it is always possible to move it slightly up/down/side with 2-finger grip.
If operator looks thru scope same time, FOV with reticle moves as well. This is perfectly normal and ok.
Same thing can happen when zooming, ocular has moving parts inside and there has to be some gap to make it work.

I´m not familiar with Vortex, but I´d imagine same thing happened there, ocular "packet" moved slightly.
If scope is FFP, it wont effect zero or POI.

Come on guys, seriously. Shoot more and worry less.

 

[tuckner]

Re: Reticle jump on FFP scopes?

Yeah, I have a Premier 3-15x50 and noticed around magnification 7 or 8 the reticle "bumps" up about .05 mil and it "bumps" back down at about 14 power. I freaked out when noticing it but upon further looking at it, the whole sight picture image does the movement as well. I can't see it during normal use, only when I am in a non-training environment when I am looking for it, slowly moving through the mag.

 

[glock24]

Re: Reticle jump on FFP scopes?

I spent time today discussing my issue with some scope manufacturers. I learned a few things that made me feel better, so I'll pass them along;

1. FFP erector tubes position the reticle at the far end (furthest from the eye). Between the reticle and your eye are two adjustable lenses that move back and forth when the magnification ring is turned

2. The fit tolerance between these two moving lenses and the erector tube is the root cause. The expensive scope manufacturers go as far as hand-fitting each lens, the other guys allow a bit more assembly tolerance.

3. If one of these two lens is too sloppy in the erector tube, the reticle and target image will bounce or shift as I've described above.

4. In <span style="text-decoration: underline">FFP scopes only</span>, both the reticle and target image shift at the same time and in the same plane. As a result, there will be no shift in POI or POA.

5. Almost all FFP scopes exhibit some level of this bounce or shift.

6. If you have this problem in a SFP scope, it does matter. SFP scopes place the reticle at the other end of the erector tube (closest to the eye). This design difference creates the potential for POA and POI changes.

 

[sobrbiker883]

Re: Reticle jump on FFP scopes?

Cool, thanks for posting your findings....