A good riflescope is essential for many types of competition, and the vast majority of hunters have scoped rifles. Some F-Class and benchrest competitors are now using optics with up to 60X magnification. Over the past 30 years, scopes have continued to evolve with improved glass, more reticle types, vastly increased elevation travel, bigger main tubes, FFP and SFP options, and even built-in electronics.

When shopping for a riflescope, it’s useful to understand how scopes work — how the internal mechanisms control windage and elevation, how parallax controls work, and how magnification levels are controlled. For today’s Saturday Showcase we feature seven videos that explain, in detail, how modern optics are constructed, and how scope components (body, lenses, controls, eyepiece etc.) function.

Scope Body Tube Engineering

The scope’s body tube is responsible for holding all riflescope components in place, and needs to be manufactured to very tight tolerances to ensure that everything lines up correctly. It is important that the body tube is crafted very uniformly and is weatherproof. Most scope tubes are aluminum for weight savings. The most common material is 6061-T6 aluminum. This offers a good balance of lightweight strength, corrosion resistance, and machinability. Schmidt & Bender and some other premium brands use 7075-T6 aluminum. This higher-grade alloy provides higher tensile and yield strength, making it more rugged under heavy recoil or harsh tactical use.

The Functions of the Many Lenses Inside a Riflescope

Riflescopes require multiple lenses, each performing a specific task. Most standard riflescopes contain at least six lens groups/elements, though complex or high-magnification tactical scopes can boast 10 to 18 individual lens elements. From front objective to rear eyepiece, a typical scope lens set includes:

• Objective Lens (Front): Gathers light (and image from the target) and forms the initial (upside-down and reversed) focal image.
• Focus / Parallax Lens: Adjusts position (often via a side-focus or adjustable objective turret) to bring the image and reticle onto the same focal plane.
• Erector Tube Lenses: Located inside the central erector assembly, these lenses flip the inverted image back to right-side up and handle zoom/magnification adjustments.
• Ocular Lens (Rear Eyepiece): Final lens closest to your eye that magnifies and focuses the finished image.

Scope Turrets — Features and Function

Turrets have come a long way over the years, but at their core, they are all responsible for the same thing — moving your erector tube to shift your point of aim via the reticle crosshairs. Elevation turrets can be set up to rotate a single time or multiple times, depending on the total elevation offered by the scope. Most scopes have perceptible clicks, which are typically set at 1/4 MOA, 1/8 MOA, or 1/10 milliradian (MIL). Recently some benchrest or extreme long-range (ELR) competition scopes have 0.05 MIL clicks.

Reticle Design, Properties, and Illumination

When choosing a scope, along with magnification, one of the most important things to consider is the reticle design — how the lines and circles appear, and whether it is a First Focal Plane (FFP) or Second Focal Plane (SFP) configuration. With a SFP scope, the lines/divisions in the reticle appear constant (unchanged) at ALL magnifications. With a FFP scope, the reticle lines/marks change in size as the scope magnification is increased or descreased. So when you zoom a FFP scope to higher magnification, the reticle will appear thicker, and importantly, the marked divisions will remain constant relative to the target.

FFP Design: A FFP reticle is placed in front of (before) the magnification erector assembly. As you increase or decrease the magnification, the reticle scales (grows or shrinks) right along with the target image. The subtensions (hash marks) remain accurate (in angular measurement) at all magnification level.

SFP Design: The SFP reticle is placed behind (after) the magnification erector assembly, near the eyepiece. As you zoom in or out, the target image changes size, but the reticle stays the same size. The hask mark subtensions (angular divisions) are only precise at one specific, manufacturer-calibrated magnification setting. This SFP design is commonly favored for benchrest and F-Class shooting at fixed distances.

Milrad vs. MOA — Key Differences

This video explains the functional differences between Milrad and MOA optics. One Milrad (milliradian or “MIL”) is about 3.3 inches height at 100 yards, so 0.1 MIL is roughly a third of an inch. One MOA is abou 1.047 inches at 100 yards, so one-quarter MOA is very close to a quarter inch at 100 yards. For benchrest, F-Class, and target shooting, MOA-based scope are most commonly used. For tactical and PRS/NRL applications, Milrad scopes are favored. Both reticle types are now popular for hunting applications. In precision shooting, the terms MIL, Milrad, MRAD, and milliradian are generally used interchangeably.

Understanding Parallax and How to Minimize Parallax Errors

The video first defines what is riflescope parallax. Then the video shows how to correct parallax and minimize it in the field. The video also explains why and how parallax errors can cause missed shots on target. After watching this video you should have a much better understanding of parallax, and how to minimize parallax issues.

How to Utilize the Diopter and Optimize the Setting

This video explains the function of a scope’s diopter control, explaining how the diopter works. The video then explains what you should be seeing through the scope and how to optimize the diopter setting quickly and efficiently. Starting at 1:40 time the video explains a 5-step process for setting the diopter properly.

Bonus READ: Nightforce Turret Tracking Tips

What Is Turret Tracking?
The term “turret tracking” refers to the precision with which a riflescope translates turret adjustments into actual point-of-impact changes. Even the smallest inconsistency in tracking can lead to missed shots, wasted ammunition, or lost opportunities in the field. Without accurate turret tracking, even a perfectly calculated firing solution won’t translate to hits on target.

Turret tracking is the relationship between what you dial on your scope’s elevation or windage turrets and how the bullet point of impact shifts downrange. This precise mechanical function is what allows shooters to make repeatable adjustments based on ballistic data. For example, if you dial 1 MRAD or 4 MOA, the bullet should land at the exact calculated offset. Any deviation means your turret isn’t tracking perfectly.

» CLICK HERE to Read Full Turret Tracking Article

At the 2018 NRA Show in Dallas last week, Trijicon unveiled a notable new scope that should interest Benchrest shooters and Long-Range competitors. The all-new Trijicon AccuPower 5-50x56mm Long Range Scope offers an impressive ten times zoom range, plus an illuminated reticle. This RS50 Series Second Focal Plane scope with 34mm main tube is offered in both MOA and MIL systems. The MOA version features 1/8 MOA clicks plus a reticle with 1 MOA subtensions at 40X power. The MIL version has 1/20 Milrad click values and a ranging style reticle with wind hold dot system. Both MOA and MIL versions have a full 100 MOA of elevation travel.

New Trijicon 5-50x56mm Scope Revealed at NRA Show in Dallas:

Credit Erik Cortina for providing this video.

With a $2700 MSRP, we expect Trijicon’s new 5-50X scope to have a “street price” of about $2400. That lines up with the NightForce 15-55x52mm Competition, now priced at $2352.00 on Amazon.

CLICK HERE for Trijicon Brochure with Full 5-50x56mm Specs »

The new Trijicon 5-50x56mm (RS50 Series) scope boasts some nice features. Employing extra-low dispersion glass, the scope offers high light transmission with minimal chromatic aberration. The magnification control lever can be moved to two different positions to suit the operator. Both MOA and MIL reticle styles are illuminated with 5 red and 5 green user-selectable brightness settings.

We hope to get our hands on one of these new Trijicon 5-50X scopes soon for testing. We’ll let you know how it stacks up against other high-magnification zoom scopes, such as the Vortex 10-60x52mm Golden Eagle, the Nightforce 15-55x52mm, and the March 5-50x56mm.

Please note, along with this 5-50x56mm scope, Trijicon has also introduced a 4.5-30x56mm RS30 Series scope. This 4.5-30X optic will be offered in both First Focal Plane and Second Focal Plane versions. SEE AccuPower Scope Brochure.