Last update on September 30, 2023 // Source: Amazon API
Rifle Scope Product Details
Swift Sport Optics Scope ST7904, Mil-Dot Side Focus 30mm, 4-12×40
The Swift Premier 4-12x40mm Rifle Scope w/Side Focus ST7904 has been created to provide you with the ideal riflescope for all of your tactical needs. This Riflescope from Swift features a Mil-dot Reticle with Medium profile turrets that make it easy to make adjustments. The Swift Premier Rifle-Scope absorbs recoil thanks to the coil spring.
Rifle Scope Product Features
Medium Profile Turrets with Caps
Coil Spring for Better Recoil Protection
30mm Tube for More Internal Adjustment
Magnification – 4-12X
About the Swift Sport Optics Scope Maker
Swift Sport Optics is a premium manufacturer for long gun scopes, optics, mounting solutions, and other accessories used for guns like rifles and long guns. They innovate and manufacture their mounts, scopes, and related products choosing materials which are resilient and long lasting. This includes the Swift Sport Optics Scope ST7904, Mil-Dot Side Focus 30mm, 4-12×40 by Swift Sport Optics. For more shooting items, visit their site.
Info About Rifle Glass
Rifle scopes permit you to exactly aim a rifle at various targets by lining up your eye with the target at range. They do this through zoom by employing a series of lenses within the scope. The scope’s alignment can be adapted for the consideration of many natural factors like wind and elevation decreases to make up for bullet drop.
The scope’s function is to understand exactly where the bullet will hit based upon the sight picture you are seeing through the optic as you align the scope’s crosshair or reticle with the intended point of impact. Many modern rifle optics have around eleven parts which are located inside and outside of the optic. These optic pieces consist of the rifle scope’s body, lenses, elevation dials, focus rings, and other components. See all eleven parts of a rifle scope.
The Varieties of Rifle Scopes
Rifle scopes can be either “first focal plane” or “second focal plane” style of scopes. The sort of focal plane a scope has establishes where the reticle or crosshair is located in regard to the optic’s magnifying adjustments. It actually suggests the reticle is located behind or in front of the magnification lens of the scope. Picking out the most desired kind of rifle optic depends on what kind of hunting or shooting you intend on doing.
First Focal Plane Glass Facts
First focal plane glass (FFP) feature the reticle before the zoom lens. This induces 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 magnified 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 identical tick at 100 yards by using 5x “zoom”. These types of scopes are beneficial for:
- Quick acquisition, far away types of shooting
- Shooting scenarios where estimations are marginal
- Experienced shooters who have an idea for their target “hold over” and “lead” equations for their long guns
- Shooters who do not mind the reticle is enlarged and uses up more visual sight space than a SFP reticle
About Second Focal Plane Optics
Second focal plane optics (SFP) come with the reticle to the rear of the magnification lens. In the FFP example with the SFP scope, the 5x “zoom” 100 yard tick would be 1/5th of the non “zoom” tick reticle measurement.
- Long distance kinds of shooting where shooters have extra time to make ballistic calculations
- Shooting where most shots happen within much shorter ranges and spaces
- Shooters who choose a clearer optic picture with less area taken up by the larger sized FFP reticle
About Scope Zoom
The amount of zoom a scope offers is determined by the size, density, and curvatures of the lenses inside of the rifle scope. The magnification of the scope is the “power” of the scope.
Fixed Single Power Lens Optics
A single power rifle optic or scope comes with a zoom number designator like 4×32. This indicates the magnification power of the scope is 4x power and the objective lens is 32mm. The zoom of this type of scope can not fluctuate since it is fixed.
Adjustable Power Lens Scope Details
Variable power rifle scopes use enhanced power. The power adjustment is performed by making use of the power ring part of the scope near the back of the scope by the eye bell.
Glass Power and Ranges
Here are some suggested scope powers and the distances where they could be effectively used. Keep in mind that higher power scopes will not be as efficient as lower magnification level scopes because too much zoom can be a negative thing in certain situations. The exact same idea applies to extended ranges where the shooter needs increased power to see exactly where to properly aim the rifle.
Rifle Scope Lens Coating
All modern-day rifle optic and scope lenses are covered. Lens finishing is an essential aspect of a rifle’s setup when thinking about high end rifle optics and scope setups.
Details on Lens Coatings – HD Versus ED
Some rifle scope companies will also use “HD” or high-definition lens coverings which make the most of different procedures, chemical applications, polarizations, and components to draw out various colors and viewable definition through lenses. This high-definition finishing is frequently used with greater density lens glass which lowers light’s potential to refract through the lens glass. Some scope suppliers use “HD” to describe “ED” implying extra-low dispersion glass. ED deals with how certain colors are presented on the chroma spectrum and the chromatic aberration or deviance which is also called color distortion or fringing. Chromatic aberration may be visible over items with well defined shapes as light hits the object from specific angles.
Details on Single Coating Versus Multi-Coating
Various optic lenses can also have various coverings applied to them. All lenses usually have at least some type of treatment or finish applied to them before they are used in a rifle scope or optic.
Single coated 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 decreasing glare and other less advantageous things experienced in the shooting environment while sighting in with the optic. The quality of a single covered lens depends on the scope manufacturer and just how much you spent paying for it. The scope’s maker and cost are indications of the lens quality.
Some scope producers similarly make it a point to define if their optic lenses are layered or “multi” coated. Being “better” depends on the maker’s lens treatment innovation and the quality of materials used in developing the rifle scope.
Optic Lens Hydrophobic Finish
Water on a lens doesn’t improve preserving a clear sight picture through a scope in any way. Many top of the line or premium scope makers will coat their lenses with a hydrophobic or hydrophilic finishing. The Steiner Optics Nano-Protection is a good example of this sort of treatment. It deals with the surface area of the Steiner scope lens so the water particles can not bind to it or produce surface tension. The outcome is that the water beads move off of the scope to keep a clear, water free sight picture.
Options for Installing Scopes on Long Guns
Mounting solutions for scopes come in a few choices. There are the basic scope rings which are separately mounted to the optic and one-piece mounts which cradle the scope. These different types of mounts also usually can be found in quick release variations which use manual levers which allow rifle shooters to rapidly install and remove the glass.
Hex Key Optic Rings
Standard, clamp design mounting scope rings use hex head screws to position to the flattop style Picatinny scope mounting rails on rifles. These varieties of scope mounts use double individual rings to support the optic, and are usually constructed from 7075 T6 billet aluminum or similar materials which are manufactured for long distance precision shooting. This kind of scope mount is great for rifles which require a durable, unfailing mount which will not change no matter just how much the scope is moved about or jarring the rifle takes. These are the design of mounts you should get for a faithful optics system on a long distance scouting or hard target interdiction long gun which will hardly ever need to be modified or recalibrated. Blue 242 Loctite threadlocker can also be used on screws to keep the hex screw threads from backing out after they are mounted securely in place. An example of these mounting rings are the 30mm type made by the Vortex Optics brand. The set generally costs around $200 USD
Quick-Release Cantilever Optic Rings
These types of quick-release rifle scope mounts can be used to quickly connect and detach a scope from a rifle. Several scopes can also be switched out if they all use a complementary designed mount. The quick detach design is CNC machined from anodized 6061 T6 aluminum and the mounting levers fasten solidly to a flat top type Picatinny rail. This enables the scope to be sighted in while on the rifle, removed from the rifle, and remounted while maintaining the original sighting settings. These types of mounts come in beneficial for shooting platforms which are hauled around a lot, to take off the glass from the rifle for protection, or for aiming systems which are employed between numerous rifles. An example of this mount style is the 30mm mount designed by Vortex Optics. It generally costs around $250 USD
Sealing and Gas Purging for Rifle Scope Tubes
Moisture inside your rifle optic can spoil a day of shooting and your costly optic by causing fogging and generating residue within the scope’s tube. Many optics protect against humidity from entering the scope tube with a system of sealing O-rings which are water resistant. Generally, these water-resistant scopes can be immersed under 20 or 30 feet of water before the water pressure can push moisture past the O-rings. This should be sufficient moisture content prevention for common use rifles for hunting and sporting purposes, unless you intend on taking your rifle on a boat and are worried about the scope still working if it goes over the side and you can still recover the firearm.
Rifle Scope Gas Purging
Another part of avoiding the accumulation of wetness inside of the rifle scope’s tube is filling the tube with a gas like nitrogen. Considering that this space is already occupied by the gas, the optic is less altered by climate changes and pressure distinctions from the outside environment which might possibly enable water vapor to permeate 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.