UTG Super Slim RDM20 Mount for SigP320 Rear Sight

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SIG P320 / P-Series · Rear-Sight-Dovetail · Docter-Footprint
UTG Super Slim RDM20: low-profile optic mount for compatible SIG rear-sight dovetails The RDM20 replaces the rear sight mount on compatible SIG P320/P-Series double-stack configurations, providing a mounting base for optics with the Docter/Venom/Noblex footprint. Two separate interfaces are therefore key: the specific rear-sight dovetail on the slide and the red dot sight's footprint.
Black Raptor assessment: with a saddle height of just 0.16 inches and a weight of 13 g, this is a slim adapter solution—but explicitly not an RMR, ACRO, or universal pistol red dot mount.

Best fit / not the best fit


Best fit if … your compatible SIG P320/P-Series double-stack model has the right rear-sight dovetail and your red dot sight uses the Docter/Venom/Noblex footprint.


Not the best fit if … your red dot uses an RMR, ACRO, Shield RMSc, or another footprint, the slide has a different optics-ready interface, or the rear sight mount's geometry does not match the intended configuration.


Features and practical benefits


0.16-inch saddle height The low-profile design keeps the red dot sight as close to the slide as possible. Note that saddle height is different from the total component height.


6061-T6 aluminum The CNC-machined aluminum construction combines low weight with a stable base for its intended use.


Dovetail insert and Torx fastener The mount uses the existing rear-sight dovetail; according to the manufacturer, no permanent modification to the slide is required.


13 g weight The low added weight is especially useful on a moving slide assembly.
it relevant and significantly lower than the 28 g previously stated in the shop text.

Limits, drawbacks, and how to avoid buying the wrong one

The most common mistake is choosing the wrong footprint: an MIL/RMR label or a visually similar mounting plate does not prove compatibility. According to the manufacturer, this version is designed for Docter-/Venom-/Noblex-compatible optics.
“P320 compatible” is also not blanket approval for every slide or optics-ready variant ever offered. Before ordering, make sure the rear-sight dovetail and optic footprint match your specific setup. According to the manufacturer, the included #6-48 screws are intended for mounting the optic; the specified T10 torque is 12 in-lb.

Technical specifications and practical notes

Footprint Docter / Venom / Noblex. Do not confuse it with RMR, ACRO, or RMSc.

Mounting base Rear-sight dovetail on compatible SIG P320 / P-Series Double-Stack models.

Dimensions Approx. 46.7 × 28 × 4.2 mm; saddle height approx. 4.1 mm separately. This keeps the adapter plate very low-profile.

Weight 0.5 oz / 13 g according to the manufacturer. The previous shop listing of around 28 g was incorrect for this SKU.

Material / finish CNC-machined 6061-T6 aluminum, matte black.

Screw interface #6-48 with T10 Torx; manufacturer specifies 12 in-lb for the intended screw connection.

Included
1 × UTG RDM20 mounting base with dovetail insert, 3 × #6-48 T10 Torx screws, 5.5 mm, 3 × #6-48 T10 Torx screws, and 1 × T10 Torx key, according to the manufacturer's parts list. Red dot sight not included.

FAQ
Will an RMR fit this mount? No. The manufacturer's exact designation for RDM-20SIG is Docter / Venom / Noblex. Will this mount fit every SIG P320? Not necessarily. The slide's specific rear-sight dovetail must match the intended geometry. Does the slide need to be permanently modified? According to the manufacturer, no permanent modification is required for the intended installation. How much does the mount weigh? The manufacturer specifies 0.5 oz or 13 g.

Black Raptor · Check both interfaces
Both the dovetail and optic footprint must fit—only then is the RDM20 the right solution. For a confirmed SIG/Docter combination, the RDM20 is a slim adapter base. If you choose based on the platform name alone or confuse RMR with Docter, you're very likely to buy the wrong mount.