Shooters often drop a ton of cash on a top-of-the-line rifle and a state-of-the-art riflescope, yet overlook the quality of their scope mounts. Your scope mount is the interface between your optic and your rifle. If you want repeatable accuracy, your scope mounts are just as important as your optic and your rifle. This is definitely not the place you want to cut corners.
Choosing the right mount deserves careful consideration. However, many shooters are unfamiliar with the different types of riflescope mounts available to modern shooters. Different firearms require different mounting systems, and often the type of mount you need will vary depending on your shooting application.
The first step in choosing an appropriate mounting system is understanding what is available. In this article, we’re going to take a look at the most common mounting options. Although volumes could be written covering all the ways optics attach to firearms, to help cut through the confusion, we’re going to keep things as simple as possible.
Table of Contents
Some traditional rifles, especially bolt actions, have special holes drilled in the receiver for attaching scope bases. Most bases are designed to fit specific rifle models, so keep this in mind when you’re shopping.
Types of Rails
Many long guns, including modern sporting rifles like the AR-15 and AR-10, have rail segments already attached to the rifle. On these firearms, the scope rings will attach directly to the rail.
Weaver Rail Mount
Weaver Multi-Slot Bases from Weaver Optics
The Weaver rail mount system was developed by William Ralph Weaver and was widely popular during the mid-1900s. It uses a pair of parallel rails with multiple slots running perpendicular to the rails.
The system originally used two pieces mounted at different points on the rifle, usually over the receiver. Unfortunately, the two-piece configuration could put undue stress on the scope during recoil. To fix the problem, the Weaver rail mount morphed into a single-piece configuration that ensures more reliable consistency and less wear-and-tear on the optic. However, a single-piece Weaver rail can inhibit access to the ejection port of some bolt-action rifles.
When to Use a Weaver Rail Mount?
With newer developments in scope mounting, the Weaver rail has waned in popularity. However, they haven’t disappeared completely from the shooting scene.
Weaver-style bases are a smart option for shooters who want a low-profile scope mount.
Picatinny Rail Mount
Picatinny rails, also called Pic rails or MIL-STD-1913 rails, were developed as a way to standardize the Weaver rail. The main difference between Weaver and Picatinny rails is the slot shapes and spacing. The slots on a Picatinny rail are squared, while Weaver-style slots have a rounded bottom. The slots on a Picatinny rail are also evenly spaced.
Picatinny rails have slightly wider and slightly deeper slots than the Weaver rail. While most Weaver-style mounts will fit on a Picatinny rail, not all Picatinny mounts will fit a Weaver rail.
The biggest advantage of a Picatinny rail is the amount of surface area available for mounting your scope rings.
When to Use a Picatinny Rail Mount?
Picatinny rails were standardized for military use in 1995. Because they work well with the M16A and M4 carbine, they are also popular choices for civilian modern sporting rifles like the AR-15.
You’ll often find Picatinny rails on the front handguard, sometimes in multiple positions, including the top, bottom, and sides.
Due to the insane popularity of the Picatinny rail, the industry is bursting with compatible accessories. That means shooters can mount more than just a traditional riflescope to their rail. If you want to trick out your AR with tactical lights, reflex sights, lasers, bipods, or bayonets, the Picatinny rail makes the process super easy.
Picatinny vs Weaver Rail – What’s the Diff?
Dovetail Rail Mount
There are no standardized dovetail mounts. Instead, the term refers to “any straight mounting bracket with an inverted trapezoid cross-section running parallel to the bore for mounting a scope or diopter sight to a rifle.”
The trapezoidal shape of the rail resembles the fanned tail of a dove, which is where the dovetail got its name. Dovetail joints have been used in woodworking for centuries, and the same stable and secure joinery can be found in the dovetail rail mount system.
Dovetail mounts are sometimes referred to as “tip-off mounts,” because they allow the shooter to easily remove or replace an optic.
When to Use a Dovetail Rail Mount?
Rails are only part of the scope-mounting equation. The rail is just the base for mounting. Attaching a scope to the rail requires rings. Rings act like clamps that tighten onto rail segments and hold the scope in place.
Rails usually have cross slots that hold the rings in place during jostling and recoil. When the rings are seated properly, they hold their positions, even when subjected to repetitive, punishing recoil.
When choosing rings, you need to be sure you select a type compatible with the rail on your rifle. While most Weaver-compatible rings will fit a Picatinny rail, there are some exceptions. However, not all Picatinny-compatible rings will fit on a Weaver rail, because the rail has smaller slots. To be on the safe side, you should verify that the rings you’re considering will work with your rail type before you buy.
When to Use Rail-Mounted Rings?
Unless you choose an alternative mounting option, you’ll need rings to mount your scope. For rails (or bases) that are segmented, rail-mounted rings make attaching your optic much easier.
Some optics come with their own mounting rings. If you need to purchase rings separately, be sure they are the right diameter for your scope and that they are compatible with your gun’s rail system.
If you have a rifle that is drilled and tapped for scope bases, there is probably a one-piece mount and ring system somewhere on the market. These mounting options are a one-stop solution. They feature a base and mounting ring fabricated from a single piece of metal. Some versions use one connected piece of metal that includes both front and rear rings all in one piece.
When to Use Integral Rings?
If you have an old-school rifle that is drilled and tapped for a scope, integral rings are the no-brainer mounting solution. They are solid, durable, and low maintenance. However, swapping out optics down the road could pose some challenges.
Other Mounting Options
Cantilever Scope Mount
Offset cantilever scope mounts were originally designed for the first M16 and AR-15 rifles. Because those first modern sporting rifles had fixed front sights and a permanent carry handle, adding a riflescope to the set-up wasn’t exactly easy or practical. Mount a regular scope over the top of the receiver and you’ll end up with the eyepiece dangerously close to your face. Not only is that position hazardous to your eye, but it also doesn’t always allow you to get an adequate sight picture.
The offset mount takes care of the issue. Although the mount attaches to the receiver as you would expect, the rings are moved forward, providing some extra and essential eye relief.
When to Use a Cantilever Scope Mount?
Most traditional, fixed stock rifles don’t pair well with an offset scope mount. However, they pair like peanut butter and jelly with old-school AR-15s.
Another option for an offset mount is on a scout rifle. The brainchild of the legendary Jeff Coper, the scout rifle is a concept that features a forward-mounted, low-power, long-eye relief scope.
Quick Attach/Detach Mount
Nicknamed QD mounts, quick attach/detach mounts are designed to do exactly what you would expect – allow fast, easy removal and attachment of an optic. These mounts usually use some sort of lever so you can almost instantly swap optics in the field.
QD mounts also ensure you don’t have to re-zero your optic with every reattachment. Instead, these mounts are engineered to maintain a spot-on zero through removal and remounting, as long as you get the optic back in the same rail position.
When to Use a QD Mount?
QD mounts are often used on tactical or 3-Gun set-ups, where the objective may require an immediate, unhindered view of your iron sights. They are also handy if you want to use the same rifle for both medium- and long-range shooting, since these disciplines may require separate optics.
Straight Talk/ Episode 1: Canted Rails For Long Range Shooting
If you want to consistently hit targets beyond 800 yards, canted mounts are something you should seriously consider. Without the right scope mount, shooting extreme distances can require holding so far over the target that you won’t be able to see it through the scope.
A canted mount helps mitigate this problem by angling the scope down toward the muzzle, adjusting the line of sight so you can still see long-range targets through the optic. Essentially, a canted mount builds in a certain degree of bullet drop so you don’t have to do all the compensating with the scope itself.
When to Use Canted Mounts?
Canted mounts are a crucial tool for extreme-range shooting. If you want to ping steel at 1000 yards, a quality set of canted mounts will help you achieve that goal.
When it comes to scope mounts (just like the optics themselves), you typically get what you pay for. Even the most expensive scope in the world becomes worthless if you use a mounting system that can’t stand up to repetitive recoil or the bumps and thumps of hard use.
Although scope mounts are often a second thought, we can’t emphasize their importance enough. Save some cash in your optics budget to acquire mounts that provide rock-solid alignment and reliable durability.