Modality of failure in scopes?

[Jaegerr]

I’ve read a lot of the different scope reviews and specifically impact tests. As someone who deals with mechanical failures of items regularly, I’m curious as to what EXACTLY separates scope A that holds zero, or scope B that can’t hold zero if you paid it. Is it a certain items/component in a scope, the way it’s put together as far as tolerances, etc. I will make the assumption it’s not the rings or the way they’re mounted for the tests as I’d imagine the same procedure is conducted for consistently.

Anyone here have any mechanical insight as to what stops a Leupold or Vortex historically to be prone to POI shift, compared to a staple product that does like NF or SWFA SS for an example?

I’m a nerd so I’m curious on the failure mode here between scopes and differences in design.

Thanks!

 

[antlerz]

Great question. It must mostly be the erector and spring mechanics. More to it than having an overweight housing. Surpised this hasn't been drilled down on. I think I saw Nightforce discuss paying attention to erector springs with polishing.
Obviously holding an adjstable reticle in an repeatable exact position within a tube is a mechanical challenge.

 

[Jaegerr]

Great question. It must mostly be the erector and spring mechanics. More to it than having an overweight housing. Surpised this hasn't been drilled down on. I think I saw Nightforce discuss paying attention to erector springs with polishing.
Obviously holding an adjstable reticle in an repeatable exact position within a tube is a mechanical challenge.

A polished spring makes a little sense in that maybe it doesn't bind or carries unreleased tension? Any variation in the spring holding the erector tube could cause a small variation. I also wonder if it potentially has to do with the rear gimble holding the tube in place in the rear. In how precise it is machined and the way it's held in place. Shooting in the dark here honestly as I'm a novice in rifle scope mechanics. I would assume it would be either variations in the elevation and windage dials, erector spring, or rear gimble as I'm not sure what other moveable variable their is in a rifle scope. If it dials repeatable manor, then one might assume it would be the erector spring or rear attachment of the erector tube?

It can't be as simple as having a better spring can it? lol

 

[RockAndSage]

I'm a novice in rifle scope mechanics

Based on the lack of durability of most scopes, it seems most rifle scope manufacturers are too.

Then again, the same can be said for almost the entirety of the gun world. Very little has moved beyond 1960s technology. Even stuff made on modern machines is often imagined with 1960s design thinking.

 

[Jaegerr]

Based on the lack of durability of most scopes, it seems most rifle scope manufacturers are too.

Then again, the same can be said for almost the entirety of the gun world. Very little has moved beyond 1960s technology. Even stuff made on modern machines is often imagined with 1960s design thinking.

I feel I’m missing something, it SEEMS like it wouldn’t take much to make any scope reliable? Especially if most are made at LOW? I feel like I’m way oversimplifying it, but what stops company X from requesting the same specs as like a Maven RS1.2 and rebranding it?

 

[RockAndSage]

I feel I’m missing something, it SEEMS like it wouldn’t take much to make any scope reliable? Especially if most are made at LOW? I feel like I’m way oversimplifying it, but what stops company X from requesting the same specs as like a Maven RS1.2 and rebranding it?

Perceived need, across the mass of the market. Few people understand how delicate their scopes are. I didn't, before coming here and seeing the mass of evidence and annecdotal confirmations. People just chalk up things like a wandering zero or losing zero after a fall to be a one-off thing. And everyone's just accustomed to checking zero before every hunt - as though that's just normal and don't even question it. Sky is blue, grass is green, always check your zero before a hunt. Ah, off by a couple of clicks? Must be atmospherics. Humidity or something. Couldn't have anything to do with a $2000 scope. Nah, no way.

What has been done here on Rokslide is about the only body of work, in the only place I'm aware of, that is actually making people aware that not only is there a problem with scope durability, but that not all scopes are subject to it. SWFA and Maven may be the only ones that perceive a bump in market demand based on drop reliability.

 

[TaperPin]

When a scope is jarred any movement inside the scope is bad. Any loose tolerances along the light path contribute to things moving. It’s my understanding the biggest source of problems has to do with the spring(s) opposite of the windage and elevation turrets that holds the part containing the reticle tightly against the adjustment screws. If it’s too light it doesn’t hold the reticle firmly and when jarred it can move out of place. Some benchrest scopes actually have a thumbscrew to lock this spring firmly in place once the turrets are adjusted, and some third party custom shops offer the installation of thumb screw on many benchrest scopes that don’t have it.

Not all lenses are held in place the same. Leupold has traditionally not used adhesive to essentially glue lenses in place like some others have. Jarring can and has moved lenses and any looseness can move impacts the amount of slop in the lens mount. I had a scope that made two distinct groups - the cause was eventually determined to be a loose lens inside the scope as it became so loose it flipped sideways. Leupold replaced the scope.

With any collection of precision parts, how well the surfaces interact with each other makes a big difference.

Since you want to go full nerd, here are some internal pics to help better visualize.

 

[TaperPin]

The erector tube spring can be a flat spring or single or double coil spring. I’ve heard of third party custom shops installing stronger springs in benchrest guns.

The weak point for bending in many scope tubes is the slot for the magnification adjustment knob. The old Leupold VX2 was not reinforced much around this slot, while VX3 scopes were thickened significantly. I stopped using VX2 scopes when I could palm the eye piece with moderate force and actually bend the tube and see it on target. I haven’t seen a stripped down scope tube on newer designs, but that slot is hard to reinforce enough to equal a fixed scope.

Here’s a Swaro showing the huge power selector cut in the tube.


The eye piece can move if the threads and lock ring are sloppy, or loosen up. I think a March scope form was testing had that problem, but it’s easy to not think about, let along check the tightness of the lock ring.

 

[Weldor]

Interesting, Thanks. I had the objective lens ring pop out on a un-named scope. It was super glued in. What looked like threads were ribs for a press fit.

 

[4th_point]

As someone who deals with mechanical failures of items regularly, I’m curious as to what EXACTLY separates scope A that holds zero, or scope B that can’t hold zero if you paid it.

I’m a nerd so I’m curious on the failure mode here between scopes and differences in design.

Hey Jaegeer,

What types of system/component failures are you dealing with? It sounds like you are involved with root cause analysis and FMEA.

I have some thoughts regarding your question, but will try to frame them so it's relevant to your background rather than a generic reply. And then you can critique my thoughts.

 

[Axlrod]

I feel I’m missing something, it SEEMS like it wouldn’t take much to make any scope reliable? Especially if most are made at LOW? I feel like I’m way oversimplifying it, but what stops company X from requesting the same specs as like a Maven RS1.2 and rebranding it?

An even better question- what stops Maven from having ALL their scopes built to the same specs as their RS 1.2?
My guess is because the RS 1.2 was a happy accident. Scope companies won't change until they are dragged kicking and screaming by a majority of their customers demanding better scopes. Other than on Rokslide it isn't happening.
A LOT of hunters 1) don't shoot much 2) don't ever achieve a properly zeroed scope 3) Take their scope caps off immediately upon arriving at their yearly "sight in" at the range, because they expect and accept that they will need to adjust the cross hairs every time.

 

[Jaegerr]

Hey Jaegeer,

What types of system/component failures are you dealing with? It sounds like you are involved with root cause analysis and FMEA.

I have some thoughts regarding your question, but will try to frame them so it's relevant to your background rather than a generic reply. And then you can critique my thoughts.

Industrial mechanical stuff (not a mechanical engineer) to be general. Welding, pumps, air actuated devices, all sorts of metallurgic stuff like chromium steel and inconel products.

 

[Jaegerr]

An even better question- what stops Maven from having ALL their scopes built to the same specs as their RS 1.2?
My guess is because the RS 1.2 was a happy accident. Scope companies won't change until they are dragged kicking and screaming by a majority of their customers demanding better scopes. Other than on Rokslide it isn't happening.
A LOT of hunters 1) don't shoot much 2) don't ever achieve a properly zeroed scope 3) Take their scope caps off immediately upon arriving at their yearly "sight in" at the range, because they expect and accept that they will need to adjust the cross hairs every time.

I vividly remember that last part as a kid lol whether it’s improperly mounted or scope failure or both I could argue.

 

[gbflyer]

I have read, with no proof of experience in assembly/disassembly, that the good scopes are bonded/epoxied/glued/what have you and a factory repair means it gets tossed in the round file and replaced. Where the scopes that are able to be disassembled and repaired don’t hold up to extreme use. This was from an industry expert on the Internet, which often times is false. This fits my confirmation bias so I’m going with it.

 

[4th_point]

Industrial mechanical stuff (not a mechanical engineer) to be general. Welding, pumps, air actuated devices, all sorts of metallurgic stuff like chromium steel and inconel products.

That's cool. You guys doing predictive maintenance or monitoring machine health? Any vibe measurements?

BTW - I see an engineering degree as a license to bullshit (BS) for some, and I have one!

 

[HNTR918]

An even better question- what stops Maven from having ALL their scopes built to the same specs as their RS 1.2?
My guess is because the RS 1.2 was a happy accident. Scope companies won't change until they are dragged kicking and screaming by a majority of their customers demanding better scopes. Other than on Rokslide it isn't happening.
A LOT of hunters 1) don't shoot much 2) don't ever achieve a properly zeroed scope 3) Take their scope caps off immediately upon arriving at their yearly "sight in" at the range, because they expect and accept that they will need to adjust the cross hairs every time.

I talked to a higher up at Maven this year.
He said that all of their scopes are built with the same design.
He said the only reason the RS1.2 passes is because the turrets hit the ground before the objective lens does.
If I were Maven, I'd be investigating this will all my marketing dollars.

 

[Jaegerr]

That's cool. You guys doing predictive maintenance or monitoring machine health? Any vibe measurements?

BTW - I see an engineering degree as a license to bullshit (BS) for some, and I have one!

Well I have a BS just not exactly in engineering so I am in fact a professional BS lol. Yes to maintenance, also major overhauls to industrial facilities. If it’s got a pipe, tube, motor, gear, or made of metal we can un-f*** it up for you!

 

[Jaegerr]

I talked to a higher up at Maven this year.
He said that all of their scopes are built with the same design.
He said the only reason the RS1.2 passes is because the turrets hit the ground before the objective lens does.
If I were Maven, I'd be investigating this will all my marketing dollars.

So while the scope is solid, it may be kind of a fluke it passes more because of the shape of the scope and less of the internals? That might get some emotion out of people

 

[ARK_Ginger]

So while the scope is solid, it may be kind of a fluke it passes more because of the shape of the scope and less of the internals? That might get some emotion out of people

I wouldn't put much in that theory. Especially without knowing what they 'design.'

My guess is that the RS1.2 is a happy byproduct of LOW using a similar Trijicon 'designed' scope construction with a Maven reticle.

 

[Jaegerr]

I wouldn't put much in that theory. Especially without knowing what they 'design.'

My guess is that the RS1.2 is a happy byproduct of LOW using a similar Trijicon 'designed' scope construction with a Maven reticle.

That’s a valid point, I don’t wanna jump to a conclusion, especially an incorrect one. It brings it back to the original question of what about the Trijicon makes it so much more reliable than a vortex? Or as durable as say a Nightforce?