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You are here: Home / Rifle Scopes / Monstrum 1-3×20 Rifle Scope with Rangefinder Reticle with Scope Rings
Monstrum Rifle Scope 1 Monstrum 1-3x20 Rifle Scope with Rangefinder Reticle with Scope Rings
Monstrum Rifle Scope 2 Monstrum 1-3x20 Rifle Scope with Rangefinder Reticle with Scope Rings
Monstrum Rifle Scope 3 Monstrum 1-3x20 Rifle Scope with Rangefinder Reticle with Scope Rings
Monstrum Rifle Scope 4 Monstrum 1-3x20 Rifle Scope with Rangefinder Reticle with Scope Rings
Monstrum Rifle Scope 5 Monstrum 1-3x20 Rifle Scope with Rangefinder Reticle with Scope Rings

Monstrum 1-3×20 Rifle Scope with Rangefinder Reticle with Scope Rings

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Check Out Monstrum 1-3×20 Rifle Scope with Rangefinder Reticle with Scope Rings. See Great Rifle Scopes By Monstrum.

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SKU: 07f71ee6abc7 Category: Rifle Scopes Tag: rifle scope
  • Description
  • Additional information

Description

Rifle Scope Product Details

Monstrum 1-3×20 Rifle Scope with Rangefinder Reticle with Scope Rings

Rifle Scope Product Features

About this item
Tactical rifle scope providing crystal clear targeting at 1-3x magnification, with a 20mm objective diameter and an eye relief of 3 Inches
Glass rangefinder reticle for on-the-fly range estimation and long distance targeting
Reticle illumination in both red and green with multiple brightness intensities for visibility in different lighting conditions
Integrated throw lever for fast and smooth adjustment of magnification dial
6061 grade aluminum construction with a 1 inch sealed, nitrogen charged tube for resistance to water and fog
Multi-Coated Clear Lens
The Monstrum S1320-R-RG is a compact tactical scope, providing crystal clear optics at 1 to 3 times magnification for close to mid-range shooting.
Crafted from aircraft grade aluminum, the scope is both sturdy and lightweight, with a 1 inch sealed, nitrogen charged tube for resistance to water and fog. The scope is 8.5 Inches in length, 2 Inches in width, 1.8 Inches in height and 11 ounces in weight.
Illuminated Rangefinder Reticle in Red or Green
The scope features an illuminated Rangefinder reticle which can be viewed in red or green illumination and in multiple brightness intensities, or viewed in black without illumination, for a suitable sight picture regardless of lighting or environment. The 1-3×20 Rifle Scope also includes an integrated throw lever allows fast and smooth adjustment of the magnification dial and a level bubble mechanism built-in to the elevation turret cap for easier scope mounting and leveling.
Responsive Turrets and Control Knobs
The package also includes a set of 1 inch high profile scope rings. The rings mount to any Picatinny or Weaver base. High profile in height, they measure 0.8 inches from the base of the mount to the bottom of the rings. Constructed from aerospace aluminum, the rings are both lightweight and durable.
The scope also comes with lens covers and one 3V CR1632 battery.
Includes: 1-3×20 Rifle Scope, Scope Rings, Battery, Lens Covers, Manual
Reticle: Illuminated Rangefinder
Materials: 6061 Aircraft Grade Aluminum
Compatibility: Rifles with Picatinny Rail
Magnification: 1-3x
Objective Diameter: 20 mm
Scope Range: Short Range, 400+ Yards
Tube Size: 1 in
Eye Relief: 3.0 in
Weight: 1lb 8oz

About the Monstrum Company

Monstrum is a premium maker for firearm scopes, optics, mounts, and other accessories used for guns like rifles and long guns. They design and build their mounts and related products by applying building materials which are long lasting and resilient. This includes the Monstrum 1-3×20 Rifle Scope with Rangefinder Reticle with Scope Rings by Monstrum. For additional shooting products, visit their website.

Rifle Scope Facts

Rifle scopes allow you to precisely aim a rifle at different targets by aligning your eye with the target at range. They accomplish this through magnifying the target by employing a set of lenses within the scope. The scope’s alignment can be adjusted for consideration of numerous environmental considerations like wind speed and elevation increases or decreases to account for bullet drop.

The scope’s purpose is to help shooters understand exactly where the bullet will hit based on the sight picture you are viewing through the optic as you line up the scope’s crosshair or reticle with the intended point of impact. The majority of modern-day rifle scopes and optics have about eleven parts which are found internally and on the exterior of the scope body. These parts consist of the rifle scope’s body, lenses, adjustment dials or turrets, objective focus rings, and other components. Learn about the eleven parts of scopes.

Rifle Glass Styles

Rifle scopes can be either “first focal plane” or “second focal plane” type of optics. Going for the optimal type of rifle glass is based around what type of shooting you plan to do.

First Focal Plane Scope Facts

Focal plane scopes (FFP) include the reticle in front of the zoom lens. These kinds of scopes are useful for:

  • Quick acquisition, far away types of shooting
  • Shooting circumstances where computations are very little
  • Experienced shooters who know their target “hold over” and also “lead” relationships for their firearms
  • Shooters who don’t mind the reticle is enlarged and occupies more visual sight area than a SFP reticle

About Second Focal Plane Scopes

Second focal plane optics (SFP) come with the reticle behind the magnifying lens. This triggers the reticle to stay at the very same size in connection with the level of magnification being used. The outcome is that the reticle measurements evolve based on the magnification used to shoot over lengthier distances because the markings represent different increments which change with the magnification level. In the FFP example with the SFP glass, the 5x “zoom” one hundred yard tick measurement would be 1/5th of the non “zoom” tick reticle measurement. These varieties of glass are beneficial for:

  • Far away styles of shooting where shooters have increased time to make ballistic calculations
  • Shooting where most shots take place within shorter spaces and ranges
  • Shooters who like a clearer optic sight picture with less area used up by the larger sized FFP reticle

Magnification for Optics

The measure of scope magnification you require depends on the sort of shooting you would like to do. Almost every style of rifle glass delivers some level of zoom. The quantity of magnification a scope supplies is identified by the dimension, density, and curvatures of the lenses inside of the rifle scope. The magnification of the optic is the “power” of the glass. This means what the shooter is aiming at through the scope is amplified times the power factor of what can generally be seen by human eyes.

Info About Single Power Lens Rifle Scopes

A single power rifle scope will have a zoom number designator like 4×32. This suggests the zoom power of the scope is 4x power while the objective lens is 32mm. The magnification of this type of optic can not fluctuate given that it is a fixed power scope.

About Variable Power Lens Scopes

Variable power rifle scopes have adjustable power. It will note the magnification degree in a format such as 2-10×32. These numbers mean the magnification of the scope can be changed between 2x and 10x power. This additionally utilizes the powers in-between 2 and 10. The power adaptation is achieved by applying the power ring component of the scope near the rear of the scope by the eye bell.

The Power Level and Range Correlation of Rifle Glass

Here are some advised scope power levels and the distances where they may be effectively used. Highly magnified optics will not be as efficient as lower magnification scopes considering that too much magnification can be a bad thing. The very same idea applies to longer ranges where the shooter needs sufficient power to see precisely where to properly aim the rifle.

Optic Lens Finishing

All modern-day rifle optic and scope lenses are covered. Lens coating is a significant aspect of a shooting platform when looking at high end rifle optics and scope setups.

About Scope Lens Coatings – HD Versus ED

Some scope suppliers also use “HD” or high-def lens finishes which use different procedures, rare earth compounds, polarizations, and components to enhance separate colors and viewable target definition through lenses. This HD covering is commonly used with more costly high density lens glass which lowers light’s ability to refract by means of the lens glass. Some scope makers use “HD” to refer to “ED” implying extra-low dispersion glass. ED deals with how certain colors are presented on the chroma spectrum and the chromatic difference or aberration which is also called color distortion or fringing. Chromatic aberration can be noticeable over things with hard outlines as light hits the item from certain angles.

Single Covering Versus Multi-Coating

Different optic lenses can likewise have different finishings applied to them. All lenses typically have at least some type of treatment or finishing used to them before they are used in a rifle scope or optic.

Single layered lenses have a treatment applied to them which is typically a protective and enhancing multi-purpose treatment. This lens treatment can preserve the lens from scratches while reducing glare and other less advantageous things experienced in the shooting environment while sighting in with the scope. The quality of a single coated lens depends on the scope developer and the amount you spent on it. Both the manufacturer and amount are indicators of the lens quality.

Some scope makers also make it a point to define if their optic lenses are layered or “multi” coated. Being “much better” depends on the maker’s lens treatment technology and the quality of materials used in constructing the rifle scope.

Hydrophobic Optic Lens Coating

Water on a scope lens does not help with preserving a clear sight picture through an optic at all. Numerous top of the line or high-end optic makers will coat their lenses with a hydrophilic or hydrophobic coating. The Steiner Optics Nano-Protection is a fine example of this type of treatment. It treats the surface area of the Steiner optic lens so the H2O particles can not bind to it or create surface tension. The outcome is that the water beads move off of the scope to keep a clear, water free sight picture.

Rifle Glass Installing Options

Installing approaches for scopes are available in a few options. There are the standard scope rings which are separately mounted to the optic and one-piece mounts which cradle the scope. These various kinds of mounts also normally are made in quick release versions which use manual levers which enable rifle operators to quickly install and dismount the scopes.

Rifle Optic Mounts with Hex Key Rings

Standard, clamp-on design mounting optic rings use hex head screws to fix to the flattop style Picatinny scope mounting rails on the tops of rifles. These styles of scope mounts use double separate rings to support the optic, and are usually constructed from 7075 T6 billet aluminum or similar materials which are made for far away precision shooting. This form of scope mount is good for rifles which are in need of a resilient, unfailing mount which will not shift regardless of just how much the scope is moved or jarring the rifle takes. These are the design of mounts you should have for a specialized scope setup on a reach out and touch someone scouting or competitors long gun which will almost never need to be altered or recalibrated. Blue 242 Loctite threadlocker can additionally be used to prevent the hex screws from wiggling out after they are installed tightly in position. An example of these mounting rings are the 30mm type made by the Vortex Optics company. The set generally costs around $200 USD

Quick-Release Cantilever Rifle Glass Ring Mounting Solutions

These types of quick-release rifle scope mounts can be used to rapidly connect and take off a scope from a rifle before reattaching it to a different rifle. Multiple scopes can also be swapped out if they all use a compatible design mount. These types of mounts come in handy for rifles which are transferred a lot, to swap out the optic from the rifle for protection, or for optics which are used in between numerous rifles or are situationally focused.

Rifle Optic Tube Sealing and Gas Purging

Wetness inside your rifle scope can mess up a day of shooting and your costly optic by bringing about fogging and developing residue inside of the scope tube. Most scopes prevent moisture from getting in the scope tube with a system of sealing O-rings which are water resistant.

Info Around Scope Tube Gas Purging

Another element of avoiding the buildup of moisture inside of the rifle scope tube is filling the tube with a gas like nitrogen. Considering that this area is currently taken up by the gas, the scope is less influenced by temperature level changes and pressure distinctions from the outside environment which might potentially enable water vapor to seep in around the seals to fill the vacuum which would otherwise be there. These are good qualities of a good rifle scope to look for.

Additional information

Category

Rifle Scopes

Brand

Monstrum

ASIN

B0851T5WPX

Reviews

Over 55

Reviews Rating

4.6 out of 5 stars

Prime

Amazon Prime

Shipping

FREE Shipping by Amazon

Best Sellers

Last update on October 4, 2026 // Source: Amazon API

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