Nikko Stirling MountMaster AO 4–12×50 HMD – NMM41250AON
Nikko Stirling MountMaster AO 4–12×50 HMD – NMM41250AON
- Brand:NIKKO STIRLING
- Product Code: MountMaster AO 4–12×50 HMD – NMM41250AON
- Availability: In Stock
89.00 € / 174.07 лв.
99.00 € / 193.63 лв.11 11 2026 11 12 2026
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Variable 4–12× magnification, a large 50 mm objective lens and adjustable parallax from just 9.1 metres. The Nikko Stirling MountMaster AO 4–12×50 is a versatile daytime riflescope with a classic matte-black finish, Half Mil Dot reticle and straightforward mechanical controls.
Multicoated optics, nitrogen filling and a protected housing are complemented by factory-supplied mounting rings for 3/8″ rails – a practical combination for compatible airgun and small-calibre sporting platforms.
Official Nikko Stirling product photograph · MountMaster AO 4–12×50 · NMM41250AON
Nikko Stirling MountMaster 4–12×50 AO HMD (NMM41250AON) combines a standard one-inch main tube, 50 mm objective lens and flexible magnification range. At 4×, the field of view is 9.6 m at 100 m, making it possible to observe a wider area. At 12×, the field narrows to 3.2 m at 100 m, enlarging distant details.
A defining feature is AO – Adjustable Objective. The front adjustment ring allows parallax adjustment from approximately 9.1 metres to infinity. This is particularly useful when observing objects at different distances and maintaining a clear relationship between the image and reticle.
The Half Mil Dot (HMD) reticle adds reference marks to a traditional crosshair. The adjustment turrets provide 1/4 MOA clicks, approximately 7 mm at 100 m. The scope uses conventional optical and mechanical systems, without requiring a battery.
The threefold zoom range lets you choose between a wider field of view and an enlarged image without changing the optical instrument.
A larger objective can collect more light than a smaller one under comparable conditions, while perceived brightness also depends on magnification.
The front adjustment provides optical control across a range of observation distances, extending to infinity.
A traditional crosshair with additional markings that provide visual angular references within the field of view.
Anti-reflective treatments help reduce unwanted reflections while supporting image clarity and contrast.
Approximately 7 mm per click at 100 m, with 60 MOA adjustment ranges for both elevation and windage.
A factory-supplied pair of rings for compatible 3/8″ dovetail rails, approximately 11 mm wide.
Nitrogen filling and a waterproof, shock-resistant construction designed to reduce internal fogging.
AO stands for Adjustable Objective. On the MountMaster, the mechanism is positioned at the front of the scope, close to the objective lens, where the distance scale is marked.
When correctly adjusted, the image of the observed subject and the reticle plane are better aligned. This reduces apparent reticle movement relative to the image when the eye changes position slightly behind the eyepiece.
The adjustment range starts at 10 yards (approximately 9.1 m) and extends to infinity. Distance markings provide a useful reference, while the best visual setting depends on actual viewing conditions.
Half Mil Dot is a reticle design with additional marks along the horizontal and vertical crosshair axes. The term “Half Mil” refers to intermediate half-milliradian references.
These markings can assist visual comparisons and understanding angular measurements. Their effective values at different magnification settings depend on the manufacturer's reticle calibration and reference magnification.
This version has a non-illuminated reticle. No batteries, electronic illumination controls or illuminated colour settings are required.
As magnification increases, distant details appear larger but the visible width of the scene decreases. On this model, the field of view is three times wider at 4× than at 12×.
Multicoated lenses: anti-reflective optical treatments reduce reflections between glass surfaces and help maintain a readable image as natural light conditions change.
Nitrogen filling: the scope contains dry nitrogen to reduce the possibility of internal condensation during temperature changes. Its metal-alloy body has a matte-black finish and a waterproof, shock-resistant construction.
Fast Eye Focus: the eyepiece provides quick individual adjustment for a clear view of the reticle. Eye relief is 85 mm, while the main tube has the standard 25.4 mm (1″) diameter.
The MountMaster AO is supplied with two mounting rings for a 3/8″ dovetail rail, a narrow profile of approximately 11 mm commonly found on certain airguns and small-calibre platforms. The scope's one-inch main tube matches the supplied rings.
Mounting rings must match this tube diameter. Standard 30 mm scope rings are not suitable.
The supplied rings fit a compatible narrow dovetail rail; they are not universal Picatinny mounts.
For a Picatinny or Weaver rail, separately selected compatible rings or a suitable mounting solution are needed. Ring height should provide adequate clearance for the 50 mm objective and the construction of the specific platform.
Close-distance AO adjustment and included rings are practical for suitable platforms equipped with compatible 11 mm rails.
Variable magnification and the HMD reticle are useful in safe, legally authorised sporting environments.
The combination of a 50 mm objective, 4–12× magnification and adjustable parallax provides flexibility for daytime viewing.
Separate magnification, eyepiece and parallax controls make the fundamentals of optical adjustment easier to understand.
Check the condition of the tube, lenses, adjustment rings and supplied mounting components.
Confirm the platform has a compatible 3/8″ rail and that the supplied one-inch rings provide adequate objective clearance.
Avoid overtightening and incompatible bases. Incorrect installation may damage the optical instrument.
Use Fast Eye Focus to make the reticle appear clear and comfortable for your individual eyesight.
The front ring provides parallax adjustment from approximately 9.1 metres to infinity.
First remove dust with an appropriate lens brush or blower, then use a clean microfiber optical cloth.
After exposure to damp conditions, dry the housing and store it in a suitable place without excessive heat or aggressive chemicals.
Never look at the sun through the scope. Always follow all safety requirements when handling airguns or firearms.
| Specification | Details |
|---|---|
| Manufacturer | Nikko Stirling |
| Series | MountMaster / Mount Master AO |
| Model | 4–12×50 AO HMD |
| Manufacturer code | NMM41250AON |
| EAN | 9420001435389 |
| Product type | Daytime riflescope with adjustable parallax |
| Magnification | Variable 4–12× |
| Objective lens diameter | 50 mm |
| Field of view at 100 m, 4× | 9.6 m |
| Field of view at 100 m, 12× | 3.2 m |
| Reticle | HMD · Half Mil Dot |
| Reticle illumination | No · non-illuminated |
| Lens coatings | Multicoated anti-reflective optics |
| Parallax adjustment | AO · Adjustable Objective |
| AO adjustment range | 9.1 m (10 yards) to infinity |
| Adjustment per click | 1/4 MOA · approximately 7 mm at 100 m |
| Elevation adjustment range | 60 MOA |
| Windage adjustment range | 60 MOA |
| Eye relief | 85 mm |
| Eyepiece adjustment | Fast Eye Focus |
| Main tube diameter | 1″ / 25.4 mm |
| Body construction | Metal alloy with matte-black finish |
| Nitrogen filled | Yes |
| Water protection | Waterproof housing |
| Internal fog resistance | Yes |
| Shock resistance | Yes, within the intended application of the series |
| Overall length | 333 mm |
| Scope weight | 403 g |
| Mounts included | Two rings for 3/8″ (approximately 11 mm) rails |
| Manufacturer warranty programme | Nikko Stirling lifetime warranty for the original owner, subject to registration and manufacturer terms |
The standard package for Nikko Stirling MountMaster AO 4–12×50 NMM41250AON includes the riflescope with its non-illuminated Half Mil Dot reticle and two mounting rings for a 3/8″ dovetail rail, sized for the one-inch tube.
The product comes in its original manufacturer packaging with accompanying materials according to the supplied batch. Alternative mounting rings, Picatinny/Weaver adapters and the host platform are not included in the standard configuration.
Nikko Stirling offers a lifetime warranty programme for its riflescopes, available to the original owner under the manufacturer's terms. Product registration is required to participate, and proof of the original purchase may be requested when submitting a warranty claim.
Misuse, abuse and unauthorised repairs are excluded. For an eligible claim, the manufacturer may repair or replace the product according to the programme conditions.
The manufacturer's lifetime programme is separate from, and does not limit, statutory consumer rights.
An introduction to the MountMaster 4–12×50 AO and its features from Nikko Stirling's official YouTube channel.
Official video source · Nikko Stirling MountMaster 4–12×50 AONMM41250AON identifies the model with front AO parallax adjustment, a non-illuminated Half Mil Dot reticle and included 3/8″ mounts.
Adjustable Objective: a front objective adjustment that controls parallax from approximately 9.1 metres to infinity.
No. NMM41250AON has a standard non-illuminated HMD reticle and needs no battery.
A crosshair with additional angular references, including half-milliradian intermediate marks. Refer to the factory reticle diagram for exact values at the specified magnification.
9.6 m at 4× and 3.2 m at 12×.
1 inch / 25.4 mm. One-inch rings are required rather than 30 mm mounts.
Yes. Two mounting rings for compatible 3/8″ (approximately 11 mm) rails are supplied.
Not directly. Picatinny or Weaver mounting requires a separately selected compatible solution for the one-inch tube.
1/4 MOA, equivalent to approximately 7 mm at 100 m.
Overall length is 333 mm, and weight is 403 g.
Yes. It is waterproof, shock-resistant and nitrogen filled to reduce internal fogging. It is not intended for submersion.
A lifetime warranty programme for the original owner, subject to product registration and the manufacturer's applicable conditions.
Contact MoskovHunt for availability, details about NMM41250AON, compatible mounting solutions and information about the Nikko Stirling warranty programme.
MoskovHunt · 37 Tsar Simeon Street, 5900 Levski, Bulgaria.
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