Monstrum G3 3-18x50 First Focal Plane FFP Rifle Scope with Illuminated MOA Reticle and…
- Rifle Scope
- 50 mm
- 3x
- 18x
- More reviewed than 88%
A first focal plane scope with accessories included that punches above its price, though the turret feel and top-end eye box are rougher than pricier optics.
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How it ranks among the 359 rifle scopes we track
4.4★ across 439 Amazon ratings, Bayesian-smoothed toward the category average.
439 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 359 rifle scopes we track - how the scorecard works · full rifle scopes data report. Confidence: medium - useful but incomplete evidence.Last refreshed Jun 22, 2026. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
An FFP rifle scope covering 3-18x magnification with a 50mm objective, illuminated MOA reticle and parallax adjustment, aimed at mid to long range shooting out to 1000 plus yards. It ships with picatinny rings, a detachable sunshade and flip-up lens covers.
Because the reticle sits in the first focal plane, the MOA markings hold their proportion at any zoom level, so holdover estimates stay accurate whether you're at 3x or 18x. Buyers who've mounted it on rifles from a .220 Swift to an AR-15 report it holding zero across hundreds of rounds. One owner weighed the scope with rings and caps at over 2 lbs, more than the listed 1 lb 5 oz spec.
- 3-18x magnification, 50mm objective
- First focal plane illuminated MOA reticle
- Parallax adjustment dial
- Includes rings, sunshade and flip-up lens covers
Who it's for
Shooters who want an FFP scope with rings and accessories bundled in at a price well under premium glass. Less suited to anyone who wants precise, audible turret clicks or plans to shoot regularly at the very top of the zoom range.
What buyers say
From Amazon customer reviews.
Reviewers consistently praise the glass clarity and zero retention across multiple firearms including a .220 Swift and an AR-15, and several call out the daylight-visible illuminated reticle. Recurring complaints include a finicky illumination knob on some units, a tighter eye box at the top of the zoom range, turret clicks that feel soft rather than sharp, and no engraved serial number.
Strengths and trade-offs
Drawn from this product's published specifications.
- Clear glass and clean tracking for the price
- Holds zero across multiple rifles and hundreds of rounds
- Reticle illumination stays visible even in daylight per one owner
- Turret clicks feel soft rather than crisp
- Eye box gets tight at the top of the magnification range
- Actual weight runs heavier than the listed spec
- No serial number engraved on the unit
Specifications
| Brand | Monstrum |
|---|---|
| Model | G3F31850-BLK |
| Dimensions & fit | |
| Objective Lens Diameter | 50 mm |
| Construction & materials | |
| Material Type | Metal |
| Color | Black |
| Compatibility & installation | |
| Mounting Type | Picatinny Mount |
| Compatible Devices | Rifle |
| Included components | |
| Unit Count | 1 |
| Included Components | G3 3-18x50 FFP Scope, 30mm High Profile Scope Rings, Lens Cleaning Cloth, Spring Loaded Flip-up Lens Covers, Sunshade |
| Warranty & support | |
| Warranty Description | Lifetime |
| Other details | |
| Magnification Minimum | 3x |
| Magnification Maximum | 18x |
| Sport Type | Hunting |
| Reticle Type | Type-H |
| Thread Type | 30mm |
| Night vision | No |
| Product Style | tactical |
Other Monstrum rifle scopes
How it compares
This product against the closest alternatives we track in rifle scopes.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| Monstrum G3 3-18x50 First Focal Plane FFP Rifle Scope with Illuminated MOA Reticle and…This product | 4.4 / 5 | 439 | 4.0 / 5 |
| UTG 3-12X44 30mm Compact ScopeUTG | 4.5 / 5 | 3,000 | 4.4 / 5 |
| Vortex Optics Diamondback Second Focal PlaneBrand | 4.7 / 5 | 1,500 | 4.3 / 5 |
| PINTY Tactical Rifle Scope Combo: Illuminated OpticsPinty | 4.4 / 5 | 1,100 | 4.3 / 5 |
| Firefield RapidStrike 1-6x24 SFP Riflescope KitFirefield | 4.5 / 5 | 900 | 4.3 / 5 |
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Questions about the Monstrum G3F31850-BLK
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
Does the reticle change size as I zoom?
No, it's first focal plane, so the MOA markings stay proportionally accurate at any magnification for range estimation.
What's included in the box?
The scope ships with a set of high-profile picatinny rings, a detachable sunshade and spring-loaded flip-up lens covers.
How heavy is it?
One buyer weighed the scope with rings and lens caps at just over 2 lbs, heavier than the 1 lb 5 oz spec listed for the scope alone.