Vortex Diamondback Tactical 4-12x40

Precision / TacticalSFPMOA1-inch tube

The Vortex Diamondback Tactical 4-12x40 is a 4-12×40 SFP scope on a 1-inch tube with a VMR-1 MOA reticle and 0.25 MOA clicks. Across its range the exit pupil runs from an estimated 10 mm down to 3.3 mm at 12×, where the twilight factor is 21.9. It is the lightest of the 26 precision scopes here, at 17.5 oz.

Approx. price: ~$450
Magnification: 4-12×
Objective: 40 mm
Weight: 17.5 oz

Best for

Dialed shooting at known and unknown distances — PRS-style matches and long-range steel

Manufacturer’s product page — not an affiliate link. Price and availability there may differ from our snapshot.

Derived optics

estimated

Exit pupil: 10–3.3 mm (4×–12×)
Twilight factor: 21.9 at 12×
Zoom ratio: 3×

Exit pupil and twilight factor are computed from the published magnification and objective diameter, not measured. Real exit pupil is also capped by the erector at low magnification, and coatings and glass quality move low-light performance in ways the formula cannot see — read these as comparisons between layouts, not verdicts on scopes.

Specifications

Manufacturer-published figures, read from vortexoptics.com. MOA/MRAD conversions use 3.438 MOA per mil.

Magnification: 4-12×
Objective lens: 40 mm
Focal plane: SFP
Reticle: VMR-1 MOA
Illuminated: No
Turret unit: MOA
Per click: 0.25 MOA (0.26″ at 100 yd)
Elevation travel: 70 MOA (≈20.4 MRAD)
Windage travel: 70 MOA
Zero stop: No
Turrets: Exposed
Parallax: Fixed 100 yd
Eye relief: 3.9″
Field of view: 23.6–7.9 ft at 100 yd
Tube: 1-inch
Length: 14.1″
Weight: 17.5 oz
Warranty: VIP unlimited unconditional lifetime

Features

SFP
MOA
1-inch tube
Exposed turrets
Fixed parallax
Lifetime warranty

For it, on paper

+ Exposed 1/4 MOA turrets with 70 MOA of elevation and windage travel on a 1 in tube
+ 17.5 oz, light for an exposed-turret scope
+ 3.9 in eye relief

Against it, on paper

− Second focal plane: the VMR-1 hash marks are only true at 12x
− Parallax fixed at 100 yd with no side focus, on a scope that goes to 12x
− No illumination
− Exposed turrets with no stated zero stop and only 12 MOA per revolution, so you count turns yourself