Q&A for ZCO 4-20x50mm Field Eval

[JGood]

That’s great the Kahles feels like it’s a superior product. However, none of those things you mentioned like “turrets” or “glass” matter if the thing can’t retain zero. Luxuries only matter if reliability is achieved first. Unfortunately most scope companies (and car companies) have prioritized the reverse of this because the market allows it.

Totally agree. I’m just pointing out why someone would want to spend more money on a scope than a $300 SWFA.

 

[Rob5589]

I bet you $5 it passes.
Form done took too long if it was gonna fail.
or he is making sure it really broke.....

Too late now but, I'm not a betting guy. Maybe I should be

 

[Dobermann]

Drop it and find out? If it fails sell it on SH

No ... that's unethical.

Simply return it, get a replacement, and sell the new scope. Known scope problem is then on the manufacturer, and you're not passing on a known problem to someone who is trusting you. Plus you'll sleep better with a clear conscience and unicorns angels will sing songs about you.

 

[Dobermann]

I know this was not directed towards me, but I think that the ZCO 420 claim to fame is the high optical image quality in a short/fast design with 50mm.

Partly ... but mainly because of Jeff Huber's involvement, the 5x erector ratio, the way they designed the spline mechanism, and more ... it's worth tracking down some of the podcasts with Jeff (mainly Frank's) to hear what the design differences are.

 

[Macintosh]

Man, you guys are like piranhas waiting for a cow to fall into the water. I’m waiting for the new rings. Not like I was shopping for a $4k scope anyway, but still…

 

[4th_point]

Partly ... but mainly because of Jeff Huber's involvement, the 5x erector ratio, the way they designed the spline mechanism, and more ... it's worth tracking down some of the podcasts with Jeff (mainly Frank's) to hear what the design differences are.

I'm aware of Huber's involvement and some of the design details, but thanks!

The question was about why one would pay extra for a 420 ZCO, a lot more. I don't think most people care about who steers the ship as long as it gets to the destination as expected.

The 420 is a compact scope. Which requires a more complicated design and is harder to manufacture to similar quality as a longer/slower scope. So it costs more.

The consumer should determine if that's a good trade off. That's it.

 

[4th_point]

Man, you guys are like piranhas waiting for a cow to fall into the water. I’m waiting for the new rings.

I have several comments and questions but am waiting for the repeat evaluation, with different rings as well.

As I see it, the first part of the eval was inconclusive regarding the scope but showed an issue with the scope rings (i.e. the scope slipped under recoil). That's disappointing since I believe that the rings are designed and manufactured in house by ZCO now.

Unless there was installation error, then I don't think it would be crazy for the consumer to wonder why ZCO released a ring that won't hold their own scope. Some might brush this off, but I see this as a fairly big deal since they make the rings and the scopes. They control (should!) the tube and ring diameters/geometry. Zero compromise? I am not seeing it. There was a process breakdown at ZCO, which should be extremely embarrassing for the organization.

Some may say that various scopes can slip in different rings, but that would be a different scenario where a ring manufacturer doesn't know what the consumer will actually be installing. For example, a 30mm tube may not actually be 30mm and could vary along its length!

I've never seen the new ZCO rings, and Formi made a comment about the fasteners, so it would be interesting to get more details on the ring design but I realize this is about the 420 scope.

Anyway, I wondered why the ZCO rings were chosen, and maybe Ryan and Formi will comment on that. There are some reports of ring compatibility issues with ZCO scopes so maybe they used ZCO rings to avoid that. Or it was by chance, who knows.

The eval results after the rings were retorqued are interesting though. Some of my questions would likely be addressed with the repeat. For example how much of the error observed was due to the rings vs scope? The rings obviously held well enough to indicate that the scope maintained zero and tracked ~OK, but the impacts showed problems. And the problems don't seem to jive with a weak spring.

I am supposed to be waiting, but went down the rabbit hole!

 

[Cactus kid]

No ... that's unethical.

Simply return it, get a replacement, and sell the new scope. Known scope problem is then on the manufacturer, and you're not passing on a known problem to someone who is trusting you. Plus you'll sleep better with a clear conscience and unicorns angels will sing songs about you.

selling a known broken scope is totally unethical. But these scopes are not “broken” by the manufacturers standards. They still function as new, they just will not hold zero. I don’t think selling a scope that doesn’t meet personal requirements is unethical.

 

[amassi]

I have several comments and questions but am waiting for the repeat evaluation, with different rings as well.

As I see it, the first part of the eval was inconclusive regarding the scope but showed an issue with the scope rings (i.e. the scope slipped under recoil). That's disappointing since I believe that the rings are designed and manufactured in house by ZCO now.

Unless there was installation error, then I don't think it would be crazy for the consumer to wonder why ZCO released a ring that won't hold their own scope. Some might brush this off, but I see this as a fairly big deal since they make the rings and the scopes. They control (should!) the tube and ring diameters/geometry. Zero compromise? I am not seeing it. There was a process breakdown at ZCO, which should be extremely embarrassing for the organization.

Some may say that various scopes can slip in different rings, but that would be a different scenario where a ring manufacturer doesn't know what the consumer will actually be installing. For example, a 30mm tube may not actually be 30mm and could vary along its length!

I've never seen the new ZCO rings, and Formi made a comment about the fasteners, so it would be interesting to get more details on the ring design but I realize this is about the 420 scope.

Anyway, I wondered why the ZCO rings were chosen, and maybe Ryan and Formi will comment on that. There are some reports of ring compatibility issues with ZCO scopes so maybe they used ZCO rings to avoid that. Or it was by chance, who knows.

The eval results after the rings were retorqued are interesting though. Some of my questions would likely be addressed with the repeat. For example how much of the error observed was due to the rings vs scope? The rings obviously held well enough to indicate that the scope maintained zero and tracked ~OK, but the impacts showed problems. And the problems don't seem to jive with a weak spring.

I am supposed to be waiting, but went down the rabbit hole!

Safe to assume they started with the zco rings and specs to avoid someone calling foul on not using their rings and specs


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[4th_point]

Safe to assume they started with the zco rings and specs to avoid someone calling foul on not using their rings and specs


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Maybe. I'd rather not assume though.

Either way, using the scope manufacturer's rings has merit so I'm not disagreeing!

 

[amassi]

Maybe. I'd rather not assume though.

Either way, using the scope manufacturer's rings has merit so I'm not disagreeing!

From following these tests a common complaint from detractors and some manufacturers is that the scopes failed because they weren’t installed to manufacture specs. Starting with their specs albeit costly in terms of ammo and time is a good practice

 

[Dobermann]

I'm aware of Huber's involvement and some of the design details, but thanks!

The question was about why one would pay extra for a 420 ZCO, a lot more. I don't think most people care about who steers the ship as long as it gets to the destination as expected.

Yeah, but if you're going on the cruise of a lifetime (or sailing into harm's way; choose your metaphor), do you want a drunken Chinese sailor who's just there to clip the ticket, or do you want an American who's been around and has a solid track record of overseeing good outcomes?

The person who is in charge sets the specs. The specs determine the reliability.

 

[4th_point]

The person who is in charge sets the specs. The specs determine the reliability.

I don't know Huber but he seems like a knowledgeable person regarding scopes. At least he can ask really good questions. I don't know that he is a technical expert though.

My background is in product development, testing, and management systems. I know what you are trying to say, but unless you are intimately familiar with the ZCO organization I don't think that Huber sets the specs. His technical person(s) do. Please correct me if I am wrong.

 

[Dobermann]

I don't know Huber but he seems like a knowledgeable person regarding scopes. At least he can ask really good questions. I don't know that he is a technical expert though.

My background is in product development, testing, and management systems. I know what you are trying to say, but unless you are intimately familiar with the ZCO organization I don't think that Huber sets the specs. His technical person(s) do. Please correct me if I am wrong.

Have you listened to his podcast with Frank? Some good info on the design and specs there ...

 

[4th_point]

Have you listened to his podcast with Frank? Some good info on the design and specs there ...

I don't know if I listened to that, but I have heard Huber speak about ZCO and his background. I recall that he clearly stated that he is not a technical person. However, he clearly understands the customer requirements. That is different than writing specs.

Tom Fuller is another person that clearly understood customer requirements when he worked with Bushnell on the DMR scope. He's not a technical expert either. That DMR scope was a success, as far as I am concerned, and Fuller was a big part of it.

In no way am I knocking Huber or Fuller. They have/had very important roles. But, technical people transform customer needs into requirements and specs.

 

[Clark33]

No ... that's unethical.

Simply return it, get a replacement, and sell the new scope. Known scope problem is then on the manufacturer, and you're not passing on a known problem to someone who is trusting you. Plus you'll sleep better with a clear conscience and unicorns angels will sing songs about you.

It was a joke boss, but thank you for the ethics lesson.

 

[4th_point]

From following these tests a common complaint from detractors and some manufacturers is that the scopes failed because they weren’t installed to manufacture specs. Starting with their specs albeit costly in terms of ammo and time is a good practice

Man, I'm totally with you.

I think that there is some merit in those complaints, while some scopes seem more robust in terms of installation than others. I think this can be confusing for a lot of consumers.

For example, I have used a BUNCH of Warne vertical split rings. Many with SWFA scopes, without any tracking or zero retention problems. And impacts much more severe than anything that I have seen posted in this forum. Yet, I don't doubt that some configurations can have problems. Some scope manufacturers and consumers do not recommend them, and I wouldn't disagree for their application if the results were negative. Lots of other choices!

Another example is dry vs lubed scope ring fasteners. Or even wet from adhesive. The torque might be the same, but the clamp load can vary. Some scopes are less robust to higher clamp load. And even the location of the ring. The reticle cell failures on the Leupo 6x is a good example. Farmer tight in the right location (wrong?!) caused problems.

I have seen some tubes crushed from excessive clamp load, and they were all wet/lubed fasteners. Not that lube/adhesive will always result in overtightening, but what if there is no visible sign of overtightening? And then the scope doesn't hold zero or is in a bind? Blame the scope, or ensure that the clamp load was not excessive?

Using the approved installation method is conservative and OK to start, then adjust if needed. We just need to perform some inspections along the way. Or, use methods that are proven to work with the knowledge that there could be other negative results?

 

[amassi]

I saw a vortex crushed by looking at it harshly. I think they want 15”# dry.
I use 25”# with loctite on nightforce, trijicon, s&b and swfa with no issues. Those scopes also tend to hold zero. I believe there’s a pretty strong correlation between scopes with strong tubes and zero retention
So when mfg throw out silly low clamp force in their instructions it isn’t surprising when they fail


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[Dobermann]

It was a joke boss, but thank you for the ethics lesson.

All good man. Hard to read intent on the internetz, especially if there's no qualifiers ... we've seen people propose exactly that kind of approach before in all seriousness.

 

[Conrad]

I have a number of ZCO's. Just to add to the sample size of data vs speculation. I had my deer rifle with 4-20 in original ARC rings fall out of the Kubota in a sliding fashion onto concrete. Scuffed up the windage knob for POI reference. Took it to my range next morning and zero was spot on, proceeded to hit the little 2"x3" plate at 200 yds and called it good. That was 2 years ago, and this switch barrel rifle gets shot a lot 200-1200, and it's always reliable.

Mount Details: curious if the ARC rings are gen 1 M10's or the gen2 MBRACE'? I have run my 5-27's in the RRS mount (excellent), M-BRACE, and the new ZCO Block (pretty new addition). One of the 5-27's sees time on a 300 NM and it is the the M-BRACE Unimount without ill affect. The other has lived on a heavy 6 dasher so I'll dismiss that for this discussion. Additionally the ZCO fasteners are T20 and T25, very good in my opinion. Way better than the chincy Spuhr screws--those blow my mind. When Area419 makes 36mm rings I'll consider some. Got a pair for my buddy's scope, and really like them.

Very recently grabbed 2 more ZCO 4-20's and they live in the ZCO slimline, but have not seen much action yet. That said I dropped one right out of the box on the ocular on my concrete floor. I did cushion the drop with my foot before it hit the floor but still managed to bend in the traveling ocular adjustment ring. I cried a little bit, and then covered the blemish with a scope cap. Scope functions fine so far. I'll probably get it repaired when I have time. I kinda like ZCO's after that the 4-16 ATACR is 2nd in line--primarily because I think that scope can survive a lot of abuse and I really like the elevation turret on it.

Just wanted to pass this along before everyone thinks they should sell their ZCO on n=1.