Last update on September 30, 2023 // Source: Amazon API
Rifle Scope Product Details
Thompson Center Arms 9948 3-9×40 3-9x 40mm Obj 36 Ft @ 100 Yds/12
Thompson Center Arms 9948 3-9×40 3-9x 40mm Obj 36 Ft @ 100 Yds/12 FtMultiX
Rifle Scope Product Features
About the Thompson Center Manufacturer
Thompson Center is a premium company for rifle scopes, optics, mounting solutions, and other accessories used for firearms like rifles and long guns. They design and supply their mounts, scopes, and related products making the most of materials which are long lasting and resilient. This includes the Thompson Center Arms 9948 3-9×40 3-9x 40mm Obj 36 Ft @ 100 Yds/12 by Thompson Center. For more shooting items, visit their site.
All About Rifle Optics
Rifle scopes allow you to specifically align a rifle at various targets by aligning your eye with the target over a distance. They do this through magnifying the target using a set of lenses within the scope. The scope’s positioning can be adapted to account for various natural things like wind speed and elevation increases to make up for bullet drop.
The scope’s function is to help shooters understand precisely where the bullet will hit based on the sight picture you are seeing via the optic as you line up the scope’s crosshair or reticle with the target. The majority of contemporary rifle scopes and optics have about 11 parts which are found within and on the exterior of the scope. These parts consist of the rifle scope’s body, lenses, adjustment dials or turrets, objective focus rings, and other parts. See all eleven parts of a scope.
Rifle Optic Styles
Rifle scopes can be either “first focal plane” or “second focal plane” kind of scopes. The kind of focal plane a scope has establishes where the reticle or crosshair is located in connection with the scopes zoom. It literally indicates the reticle is located behind or before the magnifying lens of the scope. Deciding on the very best form of rifle scope is dependent on what type of shooting you anticipate doing.
First Focal Plane Glass
Focal plane scopes (FFP) feature the reticle in front of the zoom lens. This triggers the reticle to increase in size based on the amount of magnification being used. The benefit is that the reticle measurements are the same at the magnified distance as they are at the non magnified distance. One tick on a mil-dot reticle at one hundred yards without “zoom” is still the same tick at 100 yards by using 5x “zoom”. These types of scopes are useful for:
- Quick acquisition, far away kinds of shooting
- Shooting scenarios where calculations are small
- Experienced shooters who recognize their target “hold over” plus “lead” equations for their long guns
- Shooters who do not mind the reticle is bigger and occupies more visual sight space than a SFP reticle
Second Focal Plane Scopes
Second focal plane optics (SFP) come with the reticle behind the zoom lens. In the FFP example with the SFP scope, the 5x “zoom” 100 yard tick measurement would be 1/5th of the non “zoom” tick measurement.
- Far away styles of shooting where shooters have more time to make ballistic estimations
- Shooting where most of the shots happen within shorter ranges and spaces
- Shooters who select a clearer optic sight picture with less room used up by the bigger FFP reticle
Rifle Glass Zoom
The extent of scope magnification you need is based on the kind of shooting you choose to do. Almost every kind of rifle glass provides some level of magnification. The level of zoom a scope delivers is identified by the diameter, density, and curves of the lens glass inside of the rifle scope. The magnifying level of the optic is the “power” of the scope. This suggests what the shooter is looking at through the scope is magnified times the power aspect of what can normally be seen by human eyes.
Fixed Single Power Lens Glass Facts
A single power rifle scope comes with a zoom number designator like 4×32. This means the magnification power of the scope is 4x power and the objective lens is 32mm. The zoom of this kind of scope can not fluctuate considering that it is a set power scope.
Info on Adjustable Power Lens Scopes
Variable power rifle scopes can be tweaked between magnified levels. The power adjustment is accomplished by the power ring part of the scope near the back of the scope by the eye bell.
The Power Level and Range Correlation of Rifle Scopes
Here are some advised scope powers and the ranges where they can be effectively used. High power scopes will not be as effective as lower powered scopes because too much zoom can be a negative aspect depending on your shooting distance. The same idea relates to longer ranges where the shooter needs sufficient power to see precisely where to properly aim the rifle.
Glass Lens Coating
All state-of-the-art rifle glass lenses are layered. Lens finishing is a significant aspect of a shooting platform when looking at high end rifle optics and scope equipment.
HD Versus ED Rifle Glass Lens Coatings
Some rifle glass manufacturers will also use “HD” or high-definition lens finishes which employ various procedures, polarizations, aspects, and chemicals to draw out a wide range of colors and viewable target visibility through lenses. This HD covering is commonly used with higher density glass which lowers light’s opportunity to refract by means of the lens glass. Some scope corporations use “HD” to describe “ED” signifying extra-low dispersion glass. ED deals with how certain colors are presented on the chroma spectrum and the chromatic deviance or aberration which is similarly called color distortion or fringing. Chromatic aberration is often obvious over things with hard edges and shapes as light hits the item from certain angles.
Single Covering Versus Multi-Coating for Optics
Various optic lenses can also have different coverings applied to them. All lenses usually have at least some kind of treatment or coating applied to them before being used in a rifle scope or optic. Due to the fact that the lens isn’t just a raw piece of glass, they require performance enhancing coatings. It becomes part of the finely tuned optic. It requires a coating to be applied to it so that it will be optimally functional in many types of environments, degrees of sunshine (full VS shaded), and other shooting conditions.
Single layered lenses have a treatment applied to them which is usually a protective and boosting multi-purpose treatment. This lens treatment can preserve the lens from scratches while lowering glare and other less useful things experienced in the shooting environment while sighting in with the optic. The quality of a single covered lens depends on the scope producer and how much you paid for it. The scope’s maker and cost are signs of the lens quality.
Some scope manufacturers similarly make it a point to define if their optic lenses are covered or “multi” covered. Being “better” depends on the producer’s lens treatment technology and the quality of materials used in developing the rifle scope.
Anti-water Finish for Rifle Optics
Water on a lens does not assist with keeping a clear sight picture through a scope at all. Many top of the line and high-end scope companies will coat their lenses with a hydrophilic or hydrophobic finish which is water repellent.
Optic Installation Alternatives
Installing approaches for scopes can be found in a few options. There are the standard scope rings which are individually mounted to the optic and one-piece mounts which cradle the scope. These various types of mounts also usually can be found in quick release variations which use toss levers which allow rifle shooters to quickly mount and dismount the scopes.
Rifle Scope Mounts with Hex Key Rings
Normal, clamp design mounting scope rings use hex head screws to mount to the flattop design Picatinny scope mount rails on rifles. These types of scope mounts use a couple of separate rings to support the optic, and are often made from 7075 T6 billet aluminum which is developed for long range accuracy shooting. This type of scope install is wonderful for rifles which need a resilient, sound mount which will not move no matter how much the scope is moved or abuse the rifle takes.
Glass Mounting Solutions with Quick-Release Cantilever Rings
These types of quick-release rifle scope mounts can be used to quickly attach and take off a scope from a rifle before reattaching it to a different rifle. Multiple scopes can even be switched out if they all use a similar design mount. These types of mounts are handy for long guns which are carried a lot, to swap out the optic from the rifle for protection, or for optics which are used between numerous rifles.
Rifle Glass Tube Sealing and Gas Purging
Wetness inside your rifle glass can ruin a day on the range and your highly-priced optic by resulting in fogging and developing residue inside of the scope tube. Many optics prevent moisture from entering the optical tube with a system of sealing O-rings which are waterproof. Generally, these water resistant scopes can be immersed underneath 20 or 30 feet of water before the water pressure can push moisture past the O-rings. This should be ample moisture content prevention for standard use rifles, unless you intend on taking your rifle aboard a watercraft and are concerned about the scope still functioning if it is submerged in water and you can still retrieve the firearm.
Gas Purged Rifle Glass Tubes
Another part of preventing the buildup of wetness within the rifle optic tube is filling the tube with a gas like nitrogen. Given that this area is already taken up by the gas, the glass is less impacted by climate alterations and pressure distinctions from the outside environment which may possibly allow water vapor to leak in around the seals to fill the void which would otherwise be there. These are good qualities of a good rifle scope to look for.