Monstrum P330-B Marksman 3X Prism Scope
- Rifle Scope
- 30 mm
- 3x
- 3x
- More reviewed than 98%
A strong value pick for AR shooters wanting clear glass and an illuminated reticle at 3x, though check eye relief carefully if mounting on an AK or similar side-rail setup.
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How it ranks among the 359 rifle scopes we track
4.4★ across 1,700 Amazon ratings, Bayesian-smoothed toward the category average.
1,700 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
A fixed 3x magnification prism rifle scope (model P330B-DX1) with a 30mm objective lens, illuminated red and green reticle, and single-piece machined aluminum body weighing 17 ounces, rated for targets out to 300 yards.
As a prism scope it uses a glass prism system instead of the refracting lenses in a traditional scope, which lets Monstrum fit 3x magnification into a smaller housing than a comparable variable scope. Reviewers consistently praise the glass clarity for the price, though eye relief comes up repeatedly as a limiting factor on certain rifle setups, notably side-mounted AK platforms.
- 3x fixed magnification, 30mm objective lens
- Reticle etched into glass, works with illumination off
- Single-piece machined aluminum body, 17 ounces
- Lifetime warranty from Monstrum
Who it's for
Suits AR-platform shooters wanting an affordable step up from a red dot with fixed magnification out to a few hundred yards. Reviewers with AK-pattern rifles and side mounts report the eye relief does not work well for that setup, so it is worth checking your platform's mount position first.
What buyers say
From Amazon customer reviews.
Reviewers widely praised the glass clarity and crisp reticle for the price, with several comparing it favorably to scopes costing several times as much, and multiple owners specifically noted it holds zero through repeated firing. The recurring complaint was eye relief, especially on AK-pattern rifles with side mounts, and a couple of reviewers found the base bolts loosened after 60 or more rounds and suggested adding thread locker.
Strengths and trade-offs
Drawn from this product's published specifications.
- Clear glass reported across multiple reviewers
- Reticle etched into glass, usable without illumination
- Reported to hold zero after extended use
- Red and green illumination with adjustable brightness
- Eye relief too short for some AK-pattern mounts
- Bolts reported to loosen after firing without thread locker
- Heavier than expected for its size
Specifications
| Brand | Monstrum |
|---|---|
| Model | P330B-DX1 |
| Dimensions & fit | |
| Objective Lens Diameter | 30 mm |
| Item Weight | 1.06 pounds |
| Construction & materials | |
| Material Type | Aluminum,Glass |
| Color | Black |
| Compatibility & installation | |
| Mounting Type | Picatinny Mount |
| Compatible Devices | Rifle |
| Other details | |
| Magnification Minimum | 3x |
| Magnification Maximum | 3x |
| Sport Type | Hunting |
| Reticle Type | Circle Dot |
| Night vision | No |
| Product Style | DX1 Reticle |
| Field Of View | 39.3 Feet |
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 P330-B Marksman 3X Prism ScopeThis product | 4.4 / 5 | 1,700 | 4.2 / 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 |
Similar rifle scopes from other brands
Questions about the Monstrum P330B-DX1
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
Does this scope work well on an AK-pattern rifle?
Reviewers with AK side mounts reported the eye relief does not fit comfortably, forcing an awkward cheek position, and suggested AR platforms fare better.
Does the reticle work if the battery dies?
Yes, the reticle is etched into the glass, so it remains visible without illumination, per both the listing and reviewer feedback.
Does the mount stay secure under recoil?
Most reviewers reported it holding zero, though a couple noted the base bolts backed out after around 60 shots and recommended thread locker.