Review: ZCO 840 versus March 5-42x PRS Edition

[TargetTactician]

So to start I have no affiliation with March or ZCO and paid for both my ZCO 840s and my two March 5-42x PRS Editions.

I hope this review can help anyone on the fence wondering about getting a March that's shopping it against the ZCO. I debated on not calling out the ZCO 840 to avoid it seeming like a ZCO bash post but felt it's important to share the experience I've had putting 8k+ rounds downrange using a ZCO 840 for PRS in a little over a year fairly hard use.

I switched because one of my ZCO had a mechanical issue that seems to be common with some 840s and this coincided with me getting a March cert off a prize table. I bought the March hoping it could be a replacement for the ZCOs I was losing faith in and if nothing else I hoped it would be mechanically sound with similar optical quality.

Since placing the March order I've shot 4 regional matches, 3 pro matches, and several practice days that have seen me shooting the March in a variety of lighting and weather conditions. So far the March has exceeded all my expectations and has proven to be a higher performing optic across all the conditions it has been used in.

Optics:
Both optics have really good glass but the March is a step above in clarity at least to my eyes. Couple key notes that need a mention:

• ZCO 840 are highly prone to sun glare as the sun is rising or setting to where even the sun shade wasn't enough at times. I've shot stages facing into the sun as it was rising with the March without the need to run the sun shade without issue. The features they added to address glare are something unique as none of my other optics handle sun glare as well.
• The ZCO does well on mirage but the March cuts the target mirage better while allowing you "see" the mirage direction with angle. The mirage depth of field performance feels like high end binoculars with the March.​
• The wider FOV of the March comes at the cost of it having a smaller eye box. It was a minor adjustment and I had to pay attention to eye relief more to mount the scope properly. It's not as tight as the Kahles 40x which I found to feel too tight but it is tighter than the ZCO 840.​

Turrets
The turret comparison isn't close. The March turrets are better than ZCO and are writable without messing with the tape wrap addons. I can dial quicker with more accuracy on the March versus the ZCO.

Parallax
When the ZCO parallax works its equally forgiving as the March if you have the diopter set properly. I find the adjustments a little less sensitive on the March at centerfire distances and if you are outside the "zero" parallax range with the March for a given setting the reticle moves less just outside the perfect parallax distance range. The knob is also easier get ahold of and turn on the March so adjustments are quicker on the fly (matters for rimfire PRS).

Reticle
The reticle on the March is faster to my eye for finding the correct hold overs than the Impact 1X. On the ZCO I found myself taking that split second to line count to make sure the hold was right for a 1.4 or .6 hold. The March has been faster and more intuitive. I do miss having more than a mil for a hold under on the March reticle but that has not been a issue so far. I haven't shot a tree reticle in centerfire since early 2024 and have not missed it once in over 12 pro matches.

Size:
The ZCO 840 is very large, especially with a sun shade. The March is a similar size to a 25x despite having 42x and is around 10 oz lighter despite the thicker tube.

TLDR:
The March is better and has become my primary optic of choice for competition shooting. I've already sold one of the ZCO and will likely sell the other one once it's done getting fixed.

 

[Judgeh]

Have to agree with all of it! I have the same model, and it certainly lives up to the hype. Have my second one on the way

 

[Onebadstang16]

Thanks for the feedback it’s always appreciated to hear shooters enjoying the product! The March PRS scope took a 2 day national win recently and the number of shooters looking for them and wanting them has increased quite a bit. It’s been awesome to see, thank you for the feedback and support @TargetTactician

 

[DeathBeforeDismount]

Having owned Both I concur with the review. The additional clarity in mirage while being able to still shoot on high power with the March is crazy.

I had a stage last weekend prone out to about 1K, 5 targets. I shot the stage on 40 power and could see every plate hit, adjusting wind each time. Heavy Mirage and sun glare.

The 2 biggest downsides are parallax seems to be narrower window and eyebox is not as forgiving as the ZCO. I do wish there was more than 1 mil of hold under, but the times you will use that are pretty infrequent.

But the turrets, clarity, reticle, and FOV are all a step up IMO. I will probably slowly replace or supplement my ZCO's with more marches going forward.

 

[malsa82]

It sounds like you have compared the March to the K540 as well. How would you say those two compare?

 

[Onebadstang16]

It sounds like you have compared the March to the K540 as well. How would you say those two compare?

I’m bias but here’s what we have heard from shooters who now own March scopes that had Kahles, this is not my direct opinion alone but also supported by shooters who have engaged with both.

Glass - Is better in the March and mirage cutting is superior to the Kahles, generally most have said they think ZCO/Theta had better glass than the Kahles even, and they think the March is superior to them all. The March had been said to offer much better lighting characteristics around the edges of targets and has less wash out, I don’t know this to personally be true but the saturation on the Kahles glass is more than the natural tones of the March.

Turrets - Have been given feedback that the March turrets are better compared to the Kahles, some feedback on Kahles was the Windage felt tight in turning on some optics, the click spacing was also defined as too tight and the writable turrets were praised on the March. Click feel “these March turrets are Theta good” should sum it up.

Size - March does the 5-42 in a very tight package and some have indicated they appreciate that although some have said they didn’t care as much.

FOV - let’s face it both these scopes absolutely destroy the competition in this category. The FOV On the 540 is more than that of the March (@25x 20.0mil on 540 versus 18.6 on March). However with increased FOV you do give up some eyebox, some have indicated the eyebox on the 540 was tighter than they liked, although both the March and 540 will have tighter eyeboxs than traditional optic offerings but offer significant FOV advantages.

Parallax - I think both optics will do fine but the edge has been inducted to go to the March.

Price - very much alligned