One advantage of Picatinny quad rails and M-LOK and KeyMod handguards is that you’re no longer limited to attaching accessories to the 12- and 6-o’clock positions of your rifle or shotgun. These new universal accessory systems enable you to connect devices, such as weapon lights, to locations that don’t interfere with the sighting plane.
A bulky variable optic is difficult to use in close quarters. An offset red dot mount allows shooters to rapidly fire shots in close-in shooting situations with a high-degree of accuracy. It’s faster to switch to your offset red dot than it is bringing your 8x LPVO back down to 1x.
Best Offset Red Dot Mounts
1. Arisaka Offset Optic Mount
Some offset mounts angle the optic at 35° or 45°, but Arisaka is one of the few manufacturers that allows you to choose the optimal angle. At 35°, the mount is closer to the primary optic, such as the riflescope tube. This allows for faster transitions between magnified optics for medium- to long-range engagements and non-magnified reflex sights for up close and personal. 45° provides additional clearance when using a riflescope with windage adjustment turrets that project from the scope tube.
Arisaka’s patent-pending Offset Optic Mount lets you adjust the angle by reversing the stem that attaches the optic plate to the base during assembly.
The company offers two plate heights to choose from — standard (1.5–1.8”) and tall (1.9–2.2”). The mount, machined from 6061-T6 aluminum and hard-coat anodized, only weighs 2 oz. without an optic attached. The base’s height is 0.180” above the Picatinny rail, and the length occupies three of the rail’s horizontal slots.
Arisaka offers interchangeable optics plates to accommodate various red-dot sights, such as the Aimpoint Acro, Burris Fastfire, and C-More, to the Holosun 509T, SIG Sauer Romeo 1, and Vortex Venom.
If you’re left-handed or want to practice switching shoulders, the base and optic plates are reversible and fully ambidextrous.
2. T.Rex Arms Offset Mount
T.Rex Arms’ focus is on compact, low-profile, and lightweight equipment. Considering the firm’s emphasis on manufacturing products for competition shooters and special operations forces, these products are geared toward speed.
The T.Rex Arms Offset Mount isn’t merely an angled offset Picatinny rail — it’s an angled mount with an adapter plate designed to accommodate MRD (miniature red dot) sights, such as the Trijicon RMR and Leupold DeltaPoint Pro.
You can attach the mount fore or aft of the riflescope, but rising only 0.16” above the rail, T.Rex Arms’ mount is sufficiently short and compact that it can also occupy the same space as some scope mounts, attaching under and beside them.
The mount is machined from 6061-T6 aluminum alloy bar stock and hard-coat anodized to military specifications so that there is no doubt regarding its durability and corrosion resistance.
Each mount includes a riser plate, so you can choose whether to stick to the standard base height or exceed it. Included in the package, you’ll also find needed screws and hex keys (Allen wrenches).
3. American Defense Manufacturing Offset Mount
American Defense Manufacturing is a company that produces AR-15-pattern rifles, bolt-action rifle chassis, upper and lower receivers, and spare parts and accessories. Naturally, offset mounting systems didn’t escape the company’s vision.
If you’re interested in an offset angled mount, but want a quick-detach option, American Defense Mfg. has you covered. Available for a variety of red-dot sights at either 33° or 45°, you can also choose whether you want it to be right- or left-handed.
The linked product is set to 45°, so when switching from the scope to the red dot, you simply have to cant the rifle to your left if you’re right-handed.
American Defense Mfg. uses titanium for the quick-detach lever. Although aircraft-grade aluminum is sufficiently strong as a material for an offset mount, titanium in a QD system is more robust — comparing favorably with steel alloys — and is susceptible to less of a shift during harsh weather conditions.
4. GG&G 45 Degree Offset Accessory Rail Mount
An affordable alternative for those on a budget is the GG&G 45 Degree Offset Accessory Rail Mount, designed with shotguns in mind. This offset mount weighs only 1.45 oz. and is machined from 6061-T6 aluminum billet. Although 2.5” in length, the base only needs 1” of rail to clamp to the weapon securely.
The offset mount has a countersunk locking cross bolt to reduce the possibility of the mount catching on clothing or equipment.
Unlike some competitors, GG&G’s offset mount is ambidextrous out of the box — no adjustment is necessary — so if you’re left-handed, you don’t have to worry about having the same accessibility.
Companies that manufacture offset mounting systems intend for them to be used primarily with backup optical sights; some, such as GG&G, emphasize using their mounts for other accessories. These can include laser-aiming devices or weapon lights, which can also be essential, especially in low-light environments and tactical applications.
5. TRUGLO 45° Offset Red Dot Mount
A well-known manufacturer of self-illuminated night sights for handguns, TRUGLO, also understands the importance of alternative sighting options for carbines and shotguns. An offset red dot can serve as your primary sight, but most shooters use it as a backup.
Compatible with Picatinny or Weaver mounts, the mount uses the company’s proprietary TOPS (TRUGLO Optical Plate System). This system allows you to use various adapter plates for mounting the most popular miniature red-dot sights on the market, such as the Trijicon RMR, Leupold DeltaPoint, and Vortex Viper.
Despite its lightweight CNC-machined aluminum build, TRUGLO’s mount is rated for calibers up to .45-70 Government so that it can handle the recoil of battles rifles and combat shotguns.
Using an Offset Red Dot
You can offset a backup sight in two different ways:
- Angled: An angled offset mount uses your existing rail and angles the sight by 35–50° relative to the bore axis. To use a red-dot mounted this way, you’ll cant the rifle, rotating it toward your support side.
- Piggyback: You may have noticed that some closed or tube optics, including riflescopes and reflector-type sights, have their own Picatinny rail. That’s for piggyback offset sights. The backup sight is attached directly to the magnified optic, allowing you to raise your eye from the riflescope’s eyepiece to the lens of the red dot. Piggyback mounts offer an ambidextrous option, as the angled types need to be attached to accommodate either a right- or left-handed shooter from the start.
Advantages of Using an Offset Mount
If you’ve attached a high-power riflescope with a comparatively narrow field of view, you may find that close-range targets are harder to acquire, and your situational awareness has been diminished.
Rather than sacrifice the long-range precision of a magnified optic, you can mount an offset red-dot sight as a backup or complement to it. Your magnified optic, mounted at 12 o’clock, serves as your primary sighting system in this configuration. This provides the pinpoint accuracy and power variability you need.
However, when you need to engage a target at relatively close range, whether that happens to be a steel plate or a human adversary, you simply rotate or cant the rifle to the left or right and transition to the offset sight.
The offset sight doesn’t necessarily need to be a backup. If you’re experimenting with different primary optics, leaving an offset sight on permanently has its advantages. These include:
- Ground clearance: When firing from the prone position, you may find that some rifle magazines, such as the 30-round USGI (AR-15) type, protrude, and lying low to the ground is difficult. As an angled offset mount requires that you rotate the rifle, you increase the clearance between the weapon and the ground.
- Recoil control: As you roll the rifle to access the offset sight, you’re tucking the butt more tightly into the pocket of your shoulder. Some find they can more effectively control the recoil of the weapon in this position.
- Breathing apparatus: If you’re wearing a field protective mask or respirator, whether due to the ongoing pandemic or to mitigate the effects of chemical irritants, rolling or canting the rifle allows you to bypass the canister.
- Low light: A red-dot sight, with its illuminated reticle, is easier to aim at in dark or low-light environments than riflescopes with black crosshairs. The ability to transition rapidly between the two can be a lifesaver.
An offset red-dot mount allows you to retain a relatively high-power riflescope as your primary optic and transition to a 1× Red Dot sight to rapidly acquire close-range targets. Besides the speed of switching from a magnified optic to a reflex, the illuminated reticle of a red dot also provides superior contrast under low-light conditions relative to black crosshairs.
It helps you preserve your situational awareness — a vital asset in self-defense or combat scenarios.