Description
Rifle Scope Product Details
Leupold FX-I Rimfire 4x28mm Fine Duplex
Rifle Scope Product Features
About this item
Leupold Model #58680 – FX-I Rim fire 4x28mm with Duplex reticle and Matte finish
100% Waterproof, fog proof, & shockproof
Rim fire Parallax – Parallax adjusted for 60 yards
Ultra-lightweight 1-inch main tube design
Precision 1/4 MOA finger click adjustments for wind age and elevation offer absolute repeatability and dependability over a lifetime of extreme use
Scratch Resistant Lenses – Lens surfaces are scratch resistant to military standard extreme abrasion specification
Designed, machined, and assembled in the USA
Leupold FX-I
Magnification Range: 4x
Weight: 7.5 oz.
Length: 9.2 in.
Maintube Diameter: 1 inch
Eye Relief (in) – Low: 4.5
Eye Relief (in) – High: 4.5
Linear FOV (ft/100 yd) – Low: 25.5
Linear FOV (ft/100 yd) – High: 25.5
Leupold FX-I
Relentless Performance
Leupold Rimfire riflescopes are built and tested to the same high standards as all Golden Ring riflescopes.
Lightweight, rugged performance
Unparalleled low light performance
Designed, machined, & assembled in the USA
Twilight Light Management System
Leupold’s Twilight Light Management systems delivers industry leading brightness and clarity by balancing light transmission, glare reduction, and image contrast and resolution ensuring a crisp image in any lighting condition.
Twilight Red Dot Light Management System
Designed, Machined, & Assembled in the USA
Rugged Reliability
Proprietary gas blend and seals are tested to a 33-foot depth and a multitude of pressure changes.
Every Leupold riflescope is designed to survive a minimum of 5,000 impacts on the Punisher, Leupold’s recoil simulation machine. The force of each impact is 3x the recoil of a .308 rifle.
All Leupold riflescopes are tested to perform from -40F to 160F.
FX VX-3i Rifleman VX-Freedom
Light Management System Twilight Twilight Max Twilight Twilight
Maintube Size 1 inch 1 inch, 30mm 1 inch 1 inch
Zoom Ratio 1:1 3:1 3:1 3:1
Price $$ $$$ $ $$
About the Leupold Brand
Leupold is a premium producer for rifle scopes, optics, mounts, and other add-ons used for firearms like rifles and long guns. They style and make their scopes, mounts, and related products choosing building materials which are durable and long lasting. This includes the Leupold FX-I Rimfire 4x28mm Fine Duplex by Leupold. For additional shooting items, visit their site.
Optic Details
Rifle scopes permit you to exactly aim a rifle at various targets by aligning your eye with the target over a range. They do this through magnification by employing a series of lenses inside the scope. The scope’s positioning can be dialed in to take into account different environmental factors like wind and elevation increases or decreases to account for bullet drop.
The scope’s purpose is to help the shooter understand precisely where the bullet will hit based upon the sight picture you are viewing using the optic as you line up the scope’s crosshair or reticle with the target. Most contemporary rifle scopes and optics have around eleven parts which are arranged within and externally on the optic. These parts include the rifle scope’s body, lenses, modification dials or turrets, objective focus rings, and other elements. See all eleven parts of optics.
Rifle Glass Types
Rifle scopes can be either “first focal plane” or “second focal plane” type of scopes. Finding the optimal type of rifle glass depends on what type of shooting you plan to do.
About First Focal Plane Optics
First focal plane glass (FFP) come with the reticle ahead of the magnification lens. This causes the reticle to increase in size based upon the level of zoom being used. The outcome is that the reticle measurements are the same at the amplified distance as they are at the non amplified distance. One tick on a mil-dot reticle at one hundred yards without “zoom” is still the exact same tick at one hundred yards with 5x “zoom”. These kinds of scopes work for:
- Quick acquisition, far away kinds of shooting
- Shooting scenarios where estimations are small
- Experienced shooters who have an idea for their aim point “hold over” plus “lead” ratios for their long guns
- Shooters who don’t mind the reticle is bigger and takes up more visual sight space than a SFP reticle
Info on Second Focal Plane Optics
Second focal plane optics (SFP) feature the reticle behind the magnifying lens. This induces the reticle to remain at the same overall size relative to the level of zoom being used. The outcome is that the reticle measurements alter based on the zoom applied to shoot over greater distances considering that the markings represent distinct increments which differ with the magnification level. In the FFP example with the SFP glass, the 5x “zoom” one hundred yard tick reticle measurement would be 1/5th of the non “zoom” tick measurement. These particular styles of optics are convenient for:
- Far away styles of shooting where shooters have increased time to make ballistic computations
- Shooting where most of the shots happen within much shorter ranges and proximities
- Shooters who prefer a clearer optic picture without space used up by the bigger FFP reticle
Magnification for Rifle Optics
The level of scope magnification you need on your scope depends upon the type of shooting you would like to do. Almost every type of rifle optic offers some degree of magnification. The level of magnification a scope delivers is established by the diameter, density, and curves of the lenses within the rifle optic. The magnification level of the scope is the “power” of the opic. This means what the shooter is observing through the scope is amplified times the power factor of what can usually be seen by human eyes.
Info About Single Power Lens Rifle Optics
A single power rifle optic and scope uses a zoom number designator like 4×32. This implies the magnification power of the scope is 4x power and the objective lens is 32mm. The zoom of this type of scope can not change because it is a set power scope.
Adjustable Power Lens Optic Details
Variable power rifle scopes have adjustable power. These types of scopes will list the zoom degree in a format such as 2-10×32. These numbers suggest the zoom of the scope can be changed between 2x and 10x power. This always includes the powers in-between 2 and 10. The power adjustment is achieved by employing the power ring part of the scope near the rear of the scope by the eye bell piece.
Optic Power Level and Range Correlation
Here are some advised scope power settings and the distances where they could be successfully used. Keep in mind that high magnification optics and scopes will not be as effective as lower magnification level optics and scopes because increased magnification can be a bad thing. The exact same idea goes for longer distances where the shooter needs adequate power to see precisely where to best aim the rifle.
About Lens Coverings
All modern-day rifle optic and scope lenses are coated. Lens finishing is a crucial aspect of a rifle’s setup when buying high end rifle optics and scope systems.
Details on Rifle Glass Lens Coatings – HD Versus ED
Some rifle glass manufacturers will also use “HD” or high-definition lens finishings which take advantage of various processes, components, polarizations, and chemicals to extract a wide range of colors and viewable target visibility through the lens. This high-def finishing is typically used with more costly, high density lens glass which decreases light’s potential to refract through the lens glass. Some scope producers use “HD” to describe “ED” implying extra-low dispersion glass. ED handles how certain colors are presented on the chroma spectrum and the chromatic aberration or deviance which is similarly called color distortion or fringing. Chromatic aberration may be obvious over things with defined outlines as light hits the object from various angles.
Rifle Glass Lens Single Coating Versus Multi-Coating
Various optic lenses can also have various finishings used to them. All lenses generally have at least some type of treatment or coating used to them before being used in a rifle scope or optic.
Single layered lenses have a treatment applied to them which is generally a protective and enhancing multi-purpose treatment. This lens treatment can shield the lens from scratches while lowering glare and other less advantageous things experienced in the shooting environment while sighting in with the optic. The quality of a single layered lens depends upon the scope designer and just how much you paid for it. Both the make and cost are indicators of the lens quality.
Some scope manufacturers similarly make it a point to specify if their optic lenses are layered or “multi” coated. Being “much better” depends on the producer’s lens treatment innovation and the quality of products used in developing the rifle scope.
Anti-water Finish for Rifle Optics
Water on an optic’s lens doesn’t assist with preserving a clear sight picture through a scope whatsoever. Many top of the line and high-end scope producers will coat their lenses with a hydrophilic or hydrophobic finish. The Steiner Optics Nano-Protection is a good example of this kind of treatment. It provides protection for the surface of the Steiner optic lens so the water particles can not bind to it or produce surface tension. The outcome is that the water beads sheet off of the scope to keep a clear, water free sight picture.
Rifle Scope Installing Alternatives
Mounting solutions for scopes are available in a couple of options. There are the standard scope rings which are individually mounted to the scope and one-piece scope mounts which cradle the scope. These various types of mounts also normally come in quick release versions which use toss levers which allow rifle operators to quickly install and remove the optics.
Hex Key Glass Rings
Basic, clamp-on style mounting scope rings use hex head screws to mount to the flattop design Picatinny scope mounting rails on the tops of rifles. These forms of scope mounts use double separate rings to support the optic, and are normally constructed from 7075 T6 billet aluminum or similar materials which are manufactured for far away accuracy shooting. This type of scope mount is great for rifle systems which are in need of a durable, hard use mount which will not change regardless of how much the scope is moved about or abuse the rifle takes. These are the type of mounts you should have for a specialized optics setup on a far away scouting or competition rifle which will almost never need to be changed or adjusted. Blue 242 Loctite threadlocker can also be used on screws to keep the hex screw threads from wiggling out after they are mounted safely in position. An example of these mounting rings are the 30mm style made by the Vortex Optics brand. The set typically costs around $200 USD
Scope Mounting Solutions with Quick-Release Cantilever Rings
These types of quick-release rifle scope mounts can be used to quickly connect and remove a scope from a rifle. Multiple scopes can also be switched out if they all use a similar style mount. The quick detach design is CNC crafted from anodized 6061 T6 aluminum and the mounting levers connect tightly to a flat top type Picatinny rail. This allows the scope to be sighted in while on the rifle, taken off of the rifle, and remounted back on the rifle while keeping accuracy. These types of mounts are useful and convenient for rifles which are hauled around a lot, to take off the glass from the rifle for protection, or for sight systems which are utilized in between numerous rifles. An example of this mount style is the 30mm mount from the Vortex Optics manufacturer. It normally costs around $250 USD
Rifle Scope Tube Sealing and Gas Purging
Moisture inside your rifle optic can destroy a day of shooting and your expensive optic by bringing about fogging and creating residue inside of the scope tube. Many scopes avoid moisture from entering the scope tube with a system of sealing O-rings which are water resistant.
Info Around Rifle Optic Tube Gas Purging
Another component of avoiding the accumulation of moisture inside of the rifle optic tube is filling the tube with a gas like nitrogen. Since this area is already taken up by the gas, the optic is less impacted by temp changes and pressure distinctions from the outside environment which may potentially permit water vapor to seep in around the seals to fill the void which would otherwise exist. These are good qualities of a decent rifle scope to look for.
