Riflescope Accessories: What You Actually Need (and What Can Wait)

A $2,000 riflescope on the wrong mount is a $2,000 liability. The glass doesn't matter if the scope shifts under recoil, sits too high for a consistent cheek weld, or runs out of elevation travel at 700 yards because nobody thought about a 20 MOA base. Riflescope accessories aren't glamorous, but the mounting system you choose will do more for your accuracy than any other single purchase after the scope itself.

The good news: most shooters only need two or three accessories to get their setup right. The bad news: choosing the wrong ones — or skipping the decision entirely and grabbing whatever rings are cheapest — creates problems that are hard to diagnose and expensive to fix.

TL;DR — Quick Summary▾

Scope rings or a cantilever mount are the only must-have riflescope accessory. Get the tube diameter right (1", 30mm, or 34mm — match your scope), choose the correct ring height so the objective bell clears the barrel, and pick rings for bolt-actions or a one-piece cantilever mount for AR platforms. A 20 MOA base matters if you shoot past 600 yards. Everything else — throw levers, sunshades, bubble levels, lens caps — is situational. This guide covers each accessory, when it actually matters, and when you can skip it.

Table of Contents▾

• Scope Rings vs. Cantilever Mounts: The First Decision
• How to Choose the Right Ring Height
• What Does 20 MOA Actually Mean?
• Tube Diameter: 1", 30mm, or 34mm?
• Throw Levers: Fast Magnification Changes
• Sunshades and Kill Flash Devices
• Lens Caps and Flip Covers
• Bubble Levels (Anti-Cant Devices)
• What About Scope Cleaning?
• Build Your Riflescope Accessories Kit by Use Case
• Frequently Asked Questions

Scope Rings vs. Cantilever Mounts: The First Decision

Before you think about any other riflescope accessory, you need to answer one question: how is the scope attaching to the rifle?

Two options dominate: two-piece scope rings that bolt independently to a rail or base, and one-piece cantilever mounts where the base and ring cradles are machined from a single block of aluminum.

Scope rings are the traditional choice. Each ring mounts independently, giving you control over spacing, eye relief, and height. They're lighter than one-piece mounts, sit lower over the bore, and work with a wider variety of base types — Picatinny, Weaver, dovetail, and proprietary systems like Tikka's T3x rings.

Rings are the right answer for most bolt-action rifles used in hunting and long-range precision shooting. The receiver provides a solid, continuous mounting surface, so there's no alignment concern between front and rear ring positions. Lower mounting keeps the scope closer to the bore, which reduces the height-over-bore offset that complicates holdovers at short range.

Cantilever mounts solve a specific problem that AR-platform rifles create. On an AR-15 or AR-10, the Picatinny rail runs across both the receiver and the handguard. If you mount two separate rings and one sits on the receiver while the other sits on the handguard, you've "bridged" the junction — and since the handguard can flex independently from the receiver, your zero will shift. A one-piece cantilever mount solves this by placing both ring cradles on a single base that attaches entirely to the receiver, with the front ring extending forward over the handguard without touching it.

Cantilever mounts are also the standard choice for LPVO setups (low-power variable optics, typically 1-6x or 1-10x) on tactical and competition rifles. The forward offset provides the eye relief these scopes need, and the rigid one-piece construction handles the repeated recoil of semi-automatic fire without loosening.

The trade-offs are straightforward: cantilever mounts are heavier, sit higher over the bore, and only work with Picatinny rails. Rings are lighter, mount lower, offer more flexibility, but require more care during installation to ensure alignment.

The short version:

• Bolt-action rifle (hunting, precision): scope rings
• AR-15 or AR-10 (tactical, competition, LPVO): cantilever mount
• Any rifle where the rail spans receiver + handguard: cantilever mount to avoid bridging

How to Choose the Right Ring Height

Ring height is the single most common mistake in scope mounting, and it creates problems you'll feel every time you shoulder the rifle.

The goal is to mount the scope as low as possible without the objective bell contacting the barrel. A lower scope keeps your line of sight closer to the bore, reduces the height-over-bore offset that affects point-of-impact at close range, and — most importantly — lets you maintain a natural cheek weld without craning your neck upward.

The Clearance Calculation

Here's the formula:

(Scope Tube Radius) + (Ring Height from rail to center) - (Objective Bell Radius) = Clearance

You want at least 0.125" (1/8") of clearance between the bottom of the objective bell and the barrel or rail. More is fine. Zero clearance means contact under recoil, which will damage the scope and shift your zero.

A simpler approach: measure the objective bell diameter of your scope (printed on the spec sheet — for example, a "4-16x50" scope has a 50mm objective), divide by two, and compare that to the ring height measurement from the manufacturer. Ring height is measured from the base of the ring (where it contacts the rail) to the center of the ring bore. Warne Scope Mounts publishes a detailed ring height calculator if you want to verify the math for your specific setup.

Common Objective Sizes and Ring Heights

These are general guidelines — the actual answer depends on your specific scope's bell profile, your rail height, and your rifle's barrel contour. Always verify with the manufacturer's measurements.

The "No Universal Standard" Problem

A critical detail: there is no industry standard for what "Low," "Medium," or "High" means. A "Low" ring from one manufacturer may be the same measured height as a "Medium" from another. Always check the actual measurement in inches, not just the label.

For example, Athlon's Precision Tac 30mm rings are available in Low (0.89"), Medium (1.05"), and MSR (1.443") heights. Their Precision line uses slightly different measurements — Low at 0.868" and Medium at 0.993". Same brand, different lines, different actual heights for the same label.

AR-Platform Exception

AR-15 and AR-10 rifles need taller rings (or a cantilever mount with built-in height) than bolt-actions. The inline stock design means your eye sits higher relative to the bore. MSR-height rings or a standard cantilever mount typically provide the right cheek weld for AR platforms. Trying to use low rings on an AR usually results in an awkward chin-on-stock position that's slow to acquire and impossible to hold consistently.

What Does 20 MOA Actually Mean?

A 20 MOA base or mount is tilted — the front is angled slightly downward toward the barrel, which points the scope's optical axis downward relative to the bore. This sounds counterintuitive until you understand what it solves.

Every riflescope has a limited amount of internal elevation adjustment. When you zero at 100 yards on a flat (0 MOA) base, roughly half of that adjustment range is used just to bring the reticle down to the zero point. The other half is available for dialing up to engage targets at longer range. For most scopes, that's enough to reach 500-600 yards before you "run out of dial."

A 20 MOA base pre-tilts the scope so that less adjustment is consumed by the zero, freeing up an additional 20 MOA of upward travel. Warne explains the mechanics in detail. That translates to hundreds of extra yards of range capability, depending on the cartridge and scope.

When You Need a 20 MOA Base

• You shoot at targets beyond 600 yards regularly
• Your scope has limited total elevation travel (less than 60 MOA)
• You dial elevation rather than using holdovers or a BDC reticle

When You Don't

• Your shooting stays under 500 yards
• You use a BDC or Christmas-tree reticle for range compensation (you're not dialing, so extra dial travel doesn't help)
• Your scope already has generous elevation travel (80+ MOA) and you're not shooting at extreme range

Many cantilever mounts are available in both 0 MOA and 20 MOA versions. If you're building a precision rifle for long-range work, default to 20 MOA — the only downside is a slightly different zero process, and the upside is significantly more usable range.

Tube Diameter: 1", 30mm, or 34mm?

This is the simplest decision in the entire accessory chain, and the one with zero room for error: the ring or mount tube diameter must match the scope's main tube diameter exactly.

A 30mm scope does not fit in 1" rings. A 34mm scope does not fit in 30mm rings. There are no adapters worth using. Check the scope's spec sheet, buy the matching size, and move on.

That said, understanding what the tube sizes mean helps when you're shopping for a scope:

• 1" (25.4mm): The legacy standard. Still common on hunting scopes, especially in the sub-$500 range. Adequate for most hunting applications.
• 30mm: The modern standard for mid-range and high-end scopes. The larger tube allows for more internal adjustment travel and can accommodate larger erector lenses. If you're buying a scope today, it's probably 30mm.
• 34mm: Found on premium tactical and competition scopes. The extra diameter provides even more adjustment range — critical for long-range precision shooting where you need every MOA of dial. Heavier and more expensive, with fewer ring and mount options than 30mm.

Throw Levers: Fast Magnification Changes

A throw lever is a small lever that clamps onto your scope's magnification ring, giving you a physical handle to crank the zoom quickly instead of fumbling with a smooth, low-profile adjustment ring.

Throw levers exist because of LPVOs. A 1-6x or 1-10x scope on a competition or tactical rifle needs to transition between 1x (both-eyes-open, close range) and full magnification (precision distance work) in under a second. Spinning a magnification ring with gloved or sweaty fingers under time pressure is slow and unreliable. A throw lever makes it a single, decisive motion.

Who needs one:

• LPVO users on AR platforms
• 3-gun and competition shooters
• Anyone who changes magnification frequently under time pressure

Who doesn't:

• Fixed-power scope users (nothing to adjust)
• Long-range precision shooters who set magnification before engaging (you're already at max power)
• Hunters using moderate variable scopes where magnification changes are deliberate, not urgent

Many higher-end variable scopes include a throw lever or have one available as a factory accessory. Before buying an aftermarket lever, check what came in the box.

Sunshades and Kill Flash Devices

A sunshade is a tube that threads onto the front of your scope's objective bell, extending the barrel of the scope forward by several inches. Its job is simple: block stray light from hitting the objective lens at an angle, which causes glare, reduced contrast, and lens flare.

Sunshades are most useful in bright, direct-light conditions — shooting with the sun at a low angle in front of you, or in snow-covered environments where reflected light floods the objective from every direction. They also reduce "scope glint," the reflection of sunlight off the objective lens that can reveal your position — relevant for hunting and tactical applications.

A kill flash (or anti-reflection device) is a honeycomb filter that fits over the objective for the same purpose but with a more aggressive approach. Kill flash devices virtually eliminate forward reflection at the cost of a slight reduction in light transmission and image brightness.

Most riflescopes have threaded objectives that accept screw-in sunshades. Check your scope's objective thread size before buying. Some manufacturers sell matched sunshades for their scope lines.

Lens Caps and Flip Covers

Scope lens coatings are thin, delicate, and expensive to replace. A set of lens caps is cheap insurance against scratches, dust, moisture, and impact damage during transport and field use.

Three main styles exist:

• Flip-open caps spring open with thumb pressure, giving instant access while staying attached. The most popular option for hunting and field use because you're never fumbling with loose caps when a shot appears.
• Bikini-style covers are a single flexible sleeve that stretches over both the objective and ocular ends, connected by a strap running along the top of the scope. Simple, light, and inexpensive.
• Tethered hard caps snap on firmly and hang from a lanyard when removed. More protection than flip caps, but slower to deploy.

Size flip caps by the outer diameter of your objective bell and ocular housing — not the lens diameter. Measure with calipers for an exact fit. Most aftermarket cap manufacturers publish sizing charts.

Bubble Levels (Anti-Cant Devices)

Cant — a slight tilt of the rifle to the left or right — is invisible to the shooter but devastating at distance. When a rifle is canted, the bullet doesn't just drift horizontally in the direction of the tilt. It also impacts lower than expected, because gravity is now pulling the bullet along a different axis than the scope's elevation adjustment assumes.

At 100 yards, a few degrees of cant is irrelevant. At 600 yards, 5 degrees of cant can move the bullet several inches off target — enough to miss a vital zone or a competition plate entirely. The error increases with range and the amount of elevation dialed in, which means long-range shooters are the most affected.

A bubble level — either clamped to the scope tube or mounted on the Picatinny rail — provides a visual reference to keep the rifle perfectly vertical. A quick glance at the bubble before each shot confirms you're level.

Who needs one:

• Precision long-range shooters (600+ yards)
• Competition shooters in PRS, NRL, or F-Class
• Anyone who dials significant elevation and notices unexplained horizontal dispersion

Who doesn't:

• Hunters taking shots under 300 yards (cant error is negligible at these distances)
• Shooters using BDC reticles at moderate range
• Casual range use at known distances

Bubble levels come in two mounting styles: tube-mounted (clamps around the scope tube, visible from the shooting position) and rail-mounted (attaches to a Picatinny rail slot). Tube-mounted levels are more popular because they're visible without shifting eye position from the scope.

What About Scope Cleaning?

Scope lenses have multi-layer coatings that improve light transmission and reduce glare. These coatings are harder than they were 20 years ago, but they're still thin films on glass — abrasion and improper cleaning will degrade them permanently.

The essentials:

• Lens pen: The carbon-compound tip lifts oils and fingerprints without liquid. The retractable brush handles dust. This is the single most useful cleaning tool for field use.
• Microfiber cloth: For wiping lenses clean after using a lens pen or cleaning solution. Use a clean, dedicated cloth — not one that's been in your pocket collecting grit.
• Lens cleaning solution: A few drops on a microfiber cloth for stubborn smudges. Use optics-specific solution, not household glass cleaner (ammonia can damage coatings).

What to avoid: shirt fabric (abrasive), paper towels (leave fibers and scratch), compressed air at close range (can force moisture into lens seals), and dry wiping a dusty lens (drags particles across the coating).

Always blow or brush loose dust off first, then clean. Wipe gently from the center outward in a single direction — circular motions can trap grit and create swirl marks.

Build Your Riflescope Accessories Kit by Use Case

Not every shooter needs every accessory. Here's what actually matters for each common setup:

Bolt-Action Hunting Rifle

• Scope rings (matched to tube diameter, correct height for your objective)
• Lens caps (flip-open for fast access in the field)
• Lens pen (compact cleaning in your pack)
• Skip: throw lever, sunshade, bubble level — unnecessary weight and complexity for field hunting

AR-15 with LPVO

• Cantilever mount (one-piece, avoids bridging, proper eye relief)
• Throw lever (fast 1x-to-max transitions)
• Lens caps (protect the glass during transport and handling)
• Skip: sunshade (adds length to an already long LPVO), bubble level (close-to-mid range work doesn't need it)

Long-Range Precision Rifle

• Scope rings or cantilever mount with 20 MOA cant (maximize elevation travel)
• Bubble level (eliminate cant-induced drift at 600+ yards)
• Sunshade (reduce glare during extended range sessions)
• Lens caps (protect during transport)
• Skip: throw lever (you're setting magnification before engaging, not during)

Competition / 3-Gun

• Cantilever mount (fast, rigid, repeatable)
• Throw lever (stage transitions demand instant magnification changes)
• Bubble level (PRS/NRL stages reward precision; every variable counts)
• Lens caps (for transit between stages)
• Skip: sunshade (stage design usually doesn't create direct-sun glare conditions)

Frequently Asked Questions

What size scope rings do I need?▾

Match the ring's tube diameter to your scope's main tube. Check the scope's spec sheet — it will list the tube diameter as 1" (25.4mm), 30mm, or 34mm. Buy rings in that exact size. For height, measure your objective bell diameter and use the clearance formula above, or check the scope manufacturer's recommended ring height.

Do I need a 20 MOA base?▾

If you regularly shoot past 600 yards and dial your elevation turret (rather than using holdovers or a BDC reticle), yes. A 20 MOA base gives you significantly more usable elevation adjustment for long-range work. If your shooting stays under 500 yards or you use a reticle-based system for range compensation, a standard 0 MOA base is fine.

Can I use scope rings on an AR-15?▾

Yes, but only if both rings sit entirely on the receiver — not bridging the receiver-to-handguard junction. If proper eye relief requires the front ring to sit on the handguard, use a one-piece cantilever mount instead. Bridging causes zero shift because the handguard can flex independently from the receiver.

How tight should scope ring screws be?▾

Most scope rings should be torqued to 15-18 inch-pounds on the cap screws (the screws holding the top half of the ring). Base screws that attach the ring to the rail are typically 35-55 inch-pounds. Always check the manufacturer's torque specifications — over-tightening can crush the scope tube and damage the erector system. Use an inch-pound torque wrench, not a regular wrench or Allen key with guesswork.

Do I need to lap my scope rings?▾

Ring lapping — using a lapping bar and abrasive compound to ensure both rings are perfectly aligned — is a precision step that most shooters can skip. Modern CNC-machined rings from reputable manufacturers are aligned well enough for hunting and general shooting. If you're building a dedicated precision rifle where every variable matters, lapping provides a marginal improvement in ring-to-scope contact that reduces the chance of stress marks on the tube and ensures even clamping pressure. For a hunting rifle, it's unnecessary.