Leupold Mark 4HD review: locking mil dials and side focus on a 34mm tube, and which size to buy

By the OpticVerdict Editorial Team.
Research-based review · Updated 2026-09-30

How we reviewed it: a research-based review built from the retailer's specification tables and every owner review on three Mark 4HD listings (six for the 4.5-18x52, six for the 6-24x52, five for the 2.5-10x42), and Leupold's own part-number pages and Mark 4HD series page for the manufacturer figures. Where the retailer and Leupold disagree, we print Leupold's figure. Magazine awards and test results we found as research leads but could not confirm on Leupold's site were left out. We have not bench-tested these scopes; the score is our editorial opinion and owner ratings are shown attributed to their source. See how we evaluate.

What the Mark 4HD is

The Mark 4HD is Leupold's riflescope line with a 4:1 zoom ratio. Leupold's series page lists five sizes: 1-4.5x24, 2.5-10x42, 4.5-18x52, 6-24x52 and 8-32x56. Leupold describes the line as a professional grade optical system with ZeroLock dials. Of the sizes we cover, the 1-4.5x24 and 2.5-10x42 use a 30mm tube and the 4.5-18x52 and 6-24x52 a 34mm tube.

The dials are the core of the line. Leupold offers two ZeroLock elevation dials: the M5C3 with 0.1 MIL clicks and up to 30 MIL in three revolutions, and the M1C3 with 1/4 MOA clicks and up to 71.5 MOA in three revolutions. Both have visual and tactile revolution indicators, and Leupold says the ZeroLock feature prevents inadvertent adjustments and ensures accurate return to zero. Leupold also says it builds every riflescope in its Beaverton, Oregon factory. Our MOA vs MRAD guide helps you pick the dial, and the MOA and MRAD calculator converts between them.

The 4.5-18x52 PR2-MIL: what you get

The row we review, part 183626, pairs the first focal plane PR2-MIL reticle with the M5C3 elevation dial, so the reticle and the dial both work in mils. Because the reticle is in the first focal plane, its mil marks keep their value at every magnification, which matters if you hold for wind or call misses off the reticle. Our FFP vs SFP guide explains the trade-off.

Leupold's spec table lists 36 MIL of elevation and 18 MIL of windage in 0.1 MIL clicks, 10 MIL per revolution. The side focus runs from 25 yards to infinity, which the retailer table confirms, so you can clear parallax on close targets as well as at distance. The field of view is 23.1 ft at 100 yards on 4.5x and 5.2 ft on 18x, and eye relief runs from 3.6 to 3.9 in. Divide the 52 mm objective by the magnification and the exit pupil is about 2.9 mm at 18x. For how parallax focus works, see parallax in a rifle scope.

What reviewers say

All six reviews on the retailer's page for this listing are four or five stars: five are five stars and one is four stars. None of the six names a reticle version. Of the six reviews we could read, three praise the clarity or the glass, and one reviewer calls the adjustments accurate. One reviewer laser bore-sighted it without trouble, and another writes that it is light enough for their hunting rifle.

“Very clear view. The adjustments are accurate and well defined.”

Verified Owner (WI), via OpticsPlanet

“light enough for my hunting rifle with all the zoomeies for long range steel plinking”

Verified Owner (CA), via OpticsPlanet

One reviewer weighing up the price writes that they “can't be spending unnecessary funds on ZC or ACTAR glass” and that they found “the Mark 4 would likely perform at the same level”. That is one owner's opinion, not a test.

The honest catches

No illumination on this row. Leupold lists the 183626 PR2-MIL as non-illuminated. The same listing sells illuminated PR1-MOA and PR1-MIL rows, and they cost more.

Turret feel is a matter of taste. One verified owner lists this as a con:

“Turrets not as clicky as I like.”

Verified Owner (CA), via OpticsPlanet

The reviewer who mentions ZC and ACTAR glass lists “Ret vs turret graduations” as a con; the part of that review we could read does not explain it, so we do not guess what they meant.

A thin owner record. Six reviews, none tied to a reticle version and none describing long-term use, is early feedback. The review count we have seen on Leupold's own Mark 4HD pages covers the whole series, so we do not quote it as a rating for this model.

Trade-offs, plainly

• The PR2-MIL row is non-illuminated; illuminated rows on the same listing cost more.
• 27.5 oz on a 34mm tube: 6.5 oz heavier than the 2.5-10x42 on Leupold's figures, and 34mm rings are needed (see our scope rings guide).
• One of six reviewers finds the turrets not as clicky as they like.
• Only six owner reviews, none tied to a reticle version.

Which size: 4.5-18x52, 6-24x52, 2.5-10x42 or 1-4.5x24

OpticsPlanet sells each Mark 4HD size on its own listing. Each column below is described only from its own listing and Leupold's page for that part number.

6-24x52 PR2-MIL: more reach on the same body

The 6-24x52 (183823, PR2-MIL) is for a shooter who spends more time at the top of the zoom: steel at distance, paper at the bench or a precision match. On Leupold's spec tables it shares the 4.5-18x52's 34mm tube, 27.5 oz, 14.6 in length, 36 MIL of elevation and 25 yard side focus; what changes is the range, 6x to 24x, with a 17.3 ft field of view at 6x. The same listing also sells PR2-MOA and PR3-MIL rows at the same price.

Its six reviews are five five-star and one four-star. Of the six we could read, five praise the glass or clarity, two praise the zero stop and two the turret feel. One reviewer lists price as the con, and the four-star review names the reticle's center dot, without saying which reticle row they bought:

“only problem was the center dot to small and you could lose it the shadows as well as heavy mirage.”

Verified Owner (OH), four-star review, via OpticsPlanet

“Turrets and parallax knob are large and easy to adjust on the fly”

Reviewer (TX), via OpticsPlanet

2.5-10x42 TMR: the lighter carbine size, first focal plane, fixed parallax

The 2.5-10x42 (183740, TMR) is the size for a carbine or a gas gun where weight and a wide low end matter more than reach: Leupold lists 21 oz, 12.5 in and 42.2 ft of field of view at 100 yards on 2.5x, on a 30mm tube with the M5C3 dial and 0.1 MIL clicks.

Two details on this listing trip buyers up. First, the retailer titles it Second Focal Plane, but the row it leads with, 183740, is first focal plane on Leupold's spec table. On this listing only the illuminated TMR row 183737 is second focal plane; the PR1-MOA row is first focal plane at the same price, and the illuminated rows cost more. Second, parallax: Leupold's feature text on the 183740 page mentions a 25-yard side focus, but its spec table for the part lists Precision Side Focus as No and a fixed parallax-free distance of 150 yards. We go with the spec table. One owner of the 2.5-10x42 also writes:

“I would prefer a side focus but this is fine.”

Reviewer (IN), four-star review, via OpticsPlanet

Its five reviews come from four reviewers (one wrote twice): four five-star and one four-star. Of the reviews we could read, four reviewers praise the glass and three the zero stop, one of them calling it “superior to the NF zero stop”. Two find the reticle thick, one of them at full power. Read the record with one caution: two reviewers write about an illuminated version, and the TMR row we price is not illuminated.

“The reticle is slightly thick at full power”

Pointman556 (ID), via OpticsPlanet

1-4.5x24: the Mark 4HD as an LPVO

The smallest Mark 4HD is the second focal plane 1-4.5x24. The illuminated FireDot BDC row, part 183315, has capped 1/4 MOA turrets and a fixed 150 yard parallax and weighs 18 oz on Leupold's page for that part, so it is a different kind of scope from the three above, with no side focus. Leupold's series page also lists 1-4.5x24 rows with M5C3 and M1C3 dials. We review the FireDot BDC row against Leupold's other true 1x scopes in our best Leupold LPVO guide.

Key specifications: 4.5-18x52 PR2-MIL

Figures are from the retailer's specification table for the 4.5-18x52 listing and agree with Leupold's part page where both publish one; rows marked Leupold appear only on Leupold's page. The exit pupil is our arithmetic, not a published figure. We claim no award for the Mark 4HD: the magazine awards in our research leads are not stated on Leupold's pages we checked.

Should you buy it, and what else to consider

• Buy the 4.5-18x52 PR2-MIL if you want one scope for hunting at distance and range days, dial in mils and want side focus down to 25 yards.
• Buy the 6-24x52 PR2-MIL if you shoot mostly at the top of the zoom, at steel, paper or in matches.
• Buy the 2.5-10x42 TMR for a carbine or a lighter rifle where a wide low end and less weight matter more than reach, and you can live with fixed parallax. For AR builds, see our best scope for AR-15 guide.
• Want a true 1x? The Mark 4HD 1-4.5x24 is covered in our best Leupold LPVO guide.
• Hunting with a lighter Leupold? Our Leupold VX-3HD 3.5-10x40 review covers a capped-turret hunting scope.
• Comparing the field? Start at our best long range rifle scope guide, or read the Vortex Razor HD Gen III review and the Zeiss Conquest V4 review. By cartridge: best scope for .308 and best scope for 6.5 Creedmoor.

FAQ

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