Zero Compromise ZC420 review

Chris Parkin investigates the latest addition to the UK riflescope market with the ZC420 from Austrian makers Zero Compromise.

Zero Compromise Optic is a new name to UK shooters, and has been taken on by RUAG to add another brand to their premium armoury. I received one of the new ZC420 optics with a 36mm tube and superb Tier-One unit, supplied by the new distributors.

The objective lens sits close within the outer aluminium one-piece tube. Similarly, at the rear, the ocular shows just 3.5mm inset from the quickly focusing eyepiece (with locking) surround.

Compact tube space of 40mm in front and 62mm behind the 50mm spherical saddle gives satisfactory mounting space with either twin or single piece mounts – yet it likely prefers a Picatinny rail equipped rifle.

The saddle’s left-side dial operates parallax adjustment from 25m to infinity, with zero backlash and smooth motion on the internal lens packages. Dials all show brand characteristic helical knurling for tactile grip.

An illumination dial resides adjacent, with 9mm exposed to initiate and control intensity. Removal of the cap shows the usual CR2032 battery underneath with red/green illumination controls.

Automation gives linear and lateral angular auto-shutdown, as well as a two-hour timed shut-off after inactivity, with immediate re-illumination to previous levels upon any dial interactions.

Elevation and windage dials are calibrated with 10mm/0.1mRad clicks. Both lift to unlock, with windage marked 7mRad left and right of centre within the overall 20mRad adjustment range of the tube’s internal mechanics. Elevation offers 35mRad in total with 15mRad per rotation.

An mRad revolution

Slackening twin opposing Allen screws in the outer rim of the 44m dial loosens it, and then returns it clockwise to mark the visual zero point after setup on your rifle.

The zero-stop also allows 0.5mRad/5 clicks below ‘0’ – allowing a slight negative, which is handy in field use. I like that there are no tiny internal mechanics to disassemble – all you need is an Allen key with no turret clicks once loosened, which I find off-putting.

ZC420: Specification

Magnification: 4-20 
Objective (mm): 50 
Main Tube Diameter (mm) : 36 
Click Value (MIL): 0.1 Elevation (MIL) 35 Elevation (m/100m): 350cm/ 100m 
Elevation lock: Yes 
Windage (MIL): 20 (cm/100m) 200cm / 100m 
Windage lock: Yes 
Field of View (ft/100yd): 9.3m – 2m (m/100m)
Eye Relief: 90 (mm) 3.54 (inches) 
Parallax Compensation (m) : 25 – ∞ 
Length: 325 (mm) 12.8 (inches) 
Weight: 986 (g) 34.8 (oz)
Illumination: red | green FFP
Light transmission: 92% 
Dioptre: -3 | +2 
Exit Pupil: 10,9 – 2,5 (mm) 

The downside is the lack of a decent turret rotation marker, if you are lucky enough to have all 35mRad still available after zeroing and use all three turns to access them. I had 22mRad left after zeroing on the Bergara rimfire with 20 M.O.A. rail.

A small pin stands up after each revolution is engaged, but it’s barely discernible with bare hands, never mind gloves, and although you will never lose zero, you might just find yourself having to dial all the way down and then back up to make sure you are on the second, instead of the first or third rotation, for example.

Markings are engraved on the turrets, but like the tube, the turrets are matt anodised and pick up every last grain of skin dust from human contact, leaving them looking untidy.

Ocular focus has a lock ring, but is not easily gripped

I can see the desire for anti-reflective coatings in a military world, but these seem to be extreme for this premium Austrian-made scope. ZCO promise not to have compromised on any factors that would decrease quality, with similar assurances of their engineer’s previous designing capabilities in the somewhat interwoven optical engineering world of Europe.

It’s good to see design focus on items like hardened steel components used in high-wear internal click detent mechanisms for the elevation and windage, ensuring a lifetime of repeatable tracking precision.

The ZCO certainly passed muster for me, with a well balanced and soft but still distinct tactile click for each 10mm moved.

Magnification from 4 to 20x is controlled with a grippy collar around the base of the ocular body. It features similar helical knurling for grip, and provides smooth, silent motion with no hint of internal carriage.

Grip on the turrets is excellent, with a distinct brand ‘look’

Angular field of view is wide and constant throughout the range, with no perceived tunneling on 4x. The eyepiece-focusing collar with lock ring gives a crisp reticle, but only really offers fingertip grip to tighten fully. ZCO supplies a nice elasticated neoprene cover that I really appreciate.

Big scopes and turrets don’t half make a mess of delicate walnut shotguns in the cabinet, so it’s good to cushion up when possible for their sake and that of the scope.

Reticle insight

In use, the optical qualities of the scope were hard to fault, although I wasn’t personally a fan of the busy MPCT2 Christmas tree reticle. I preferred the cleaner MPCT1 with fewer elements in the left and right lower quadrants, particularly when bullet holes or off-target splash needed observation.

Reticle etching and the ocular lens gave perfect crisp rendition of the First Focal Plane reticle, with heavier outer 12, 3 and 9 o’clock arms surrounding
an illuminated centre hanging reticle with a floating dot.

At full magnification, it is easy to read the 7.3mRad marked by each arm to calculate a 14.6mRad field of view, which at 100 metres, equates to 1.46 metres.

Reticles are a very personal choice; Chris prefers the MPCT1, a simple design without the lower ‘Christmas tree’

Online data sheets are plentiful, but I find it odd that ZC, a European company with a straightforward metric scope using base 10, oddly give published specification data in a mixture of – often clumsy – imperial and metric units for targets in M.O.A.

I think it is better to concentrate entirely on one system to avoid small errors creeping into calculations where flying bullets are present.

0.2 and 0.5 hash markings are shown on the reticle, with image quality flat and crisp right out to the edges. A 0.1 mil ranging bracket is placed between the 4–5 mil points for accurate ranging capability, and to keep the view uncluttered in the outer quadrants for target observation.

The rotation indicator needs to be a bit more tactile with bare fingers, never mind gloves

However, at lower magnification (where full field is exposed) and smaller reticle appearance, these can become a struggle to view.

When it came to pure image quality, the ZCO was impressive. A quoted light transmission factor of 92 per cent was utterly believable, with good colour balance and contrast – quite vivid in daylight mid-June, but also retained into the evening and dusk of the later shots that occur during midsummer’s long days.

Little goes a long way

Optical detail and resolution remained linearly in line with diminishing light, and didn’t seem to suffer a distinct ‘step’ down as darkness closed. Eye relief at 90mm looks short in these days of ‘100mm promises for magnum calibres’, but longer eye relief comes at the slight expense of exit pupil, field of view and eye box versatility.

It’s no surprise to see the ZCO following similar competitors’ optics who also stay at 90mm to retain the relaxed optical environment with generous spacial movement without vignettes.

Chris also appreciates the protection offered by these neoprene covers for the scope and its other cabinet or travel companions

Its compact overall length and shorter eye relief actually make it very suited to long-range rimfires, although the price perhaps dictates that it might be too luxurious for that market. Even on centrefires in the past, I had no contact with the eye bell surrounding the 40mm ocular lens.

Only time will tell if this brand can justify its high prices, with no particular reputation other than that of an Austrian manufacture and a lifetime transferable warranty, yet all electronics are still locked in at two years like most of its peers.

ZC420: hunt it down

Zero Compromise Optic ZC420
Price: £3,250 RRP
Contact: RUAG, 01579 362319,

More Sporting Rifle review

Tagged with: , , , , , , , , , , , , , , , , , , , , , , , , , , ,
Posted in Reviews

Leave a Reply

Your email address will not be published. Required fields are marked *


Follow Us!