The EGW Sig Sauer P220–229, 320 Trijicon RMR Sight Mount is a dovetail-mounted adapter designed to let you run a modern red dot on classic Sig pistols without gunsmithing. Built from 7075 aluminum with a matte black hardcoat finish, this mount replaces your factory rear sight and accepts Trijicon RMR and Holosun HS507C optics. It's a straightforward swap—no alterations to your gun, and you can reinstall the original sight anytime.
This mount covers a wide range of Sig legacy and polymer-frame models, from the P220 and P226 through the P229, P239, P245, and P320, as well as Bersa Thunder and FN 509 pistols. The compact footprint (1.780" long, 1.1" wide) keeps weight and profile minimal, so your concealed carry or duty gun stays as trim as possible. Installation is straightforward: remove the rear sight, slide the mount into the dovetail, and secure it with the included 6-32 screws and set screw. All hardware is provided, and the screws require a 5/64" Allen wrench.
Important note: this mount does not work with factory Optics Ready Sig pistols (like the P226 Legion RX, P229 RX, or P320 X-Carry), the P365, or Sig 1911s. If your gun already has a factory red dot cut, you'll need a different solution. For everything else on the supported list, EGW's mount offers a no-fuss way to modernize iron-sight pistols without permanent modifications.
Key Features
- Replaces factory rear sight—no gunsmithing required
- Accepts Trijicon RMR and Holosun HS507C red dots
- Reversible: reinstall original sights anytime
- Compact aluminum construction with matte black hardcoat
- All mounting hardware included
- Supports P220, P226, P229, P320, and many other legacy/polymer Sig models plus select Bersa and FN 509 pistols
Specifications
| Material | 7075 Aluminum |
| Finish | Matte Black Hardcoat |
| Overall Length | 1.780" |
| Overall Width | 1.1" |
| Red Dot Compatibility | Trijicon RMR, Holosun HS507C |
| Included Hardware | 2× 6-32 Flat Head Screws, 1× 6-32 × 3/16 Set Screw |
| Allen Wrench Size | 5/64" |
| Recommended Torque | 15 in-lbs |
Frequently Asked Questions
Will this mount fit my Sig P320 X-Carry or P226 Legion RX?
No. This mount does not work with factory Optics Ready Sig pistols, including the P320 X-Carry, P226 Legion RX, P229 RX, or any other gun with a pre-cut red dot pattern. It's designed for classic dovetail-mounted rear sights only.
What red dot sights work with this mount?
The EGW mount is compatible with Trijicon RMR and Holosun HS507C optics. These are the only red dots tested and confirmed to fit this adapter.
Do I need to modify my gun to install this?
No. Simply remove your factory rear sight and install the EGW mount into the dovetail—no gunsmithing, drilling, or alteration required. You can remove the mount and reinstall your original sight at any time.
What pistols does this mount fit?
Compatible guns include Sig P220, P224, P225, P225-A1, P226, P227, P228, P229, P238, P239, P245, P320, P938, SP2022, and M11-A1; Bersa Thunder UC and HC series (9/40/45); and FN 509. It does not fit 1911s, Optics Ready Sigs, the P210 Target, P365, or FN 509 Tactical.
