C+HPrecision Optics Adapter Plate with 10-8 Rear Sight for SIG P320 Legion (X-Five/M17/M18) with Romeo 1 Pro Optic Ready Cut and Trijicon RMR/SRO, Holosun 407C/507C/508C/508T

This product fixed the mounting issues I was having with my RMR sight. Now my RDO is fitted, snug and holding zero. It seems that the stock mounting holes in the Legion slide is too short and the thread size/pitch didn’t match the screws that came with my sight. No mater what I tried, I just couldn’t get the sight mounted securely. At least not until I got this adapter plate. This adapter plate is over engineered and is attached using the larger screw holes available in the slide. The adapter plate provides pegs for the RDO to align with as well as its own screws to attach the RDO to the plate. All in all a very well designed product for a very specific application to solve a unique issue of mounting any RMR RDO to the P320 X5 Legion. This is a must have and worth every penny for the amount of time and frustration it will save you.

Paired with a SwampFox Liberty (with the Ironsides Shield). The little 'legs' for the plate threw me off a little, but a quick call to C+H Precision's customer service and my confidence was restored. I'm using the OEM front site, and the red dot disappears perfectly when the front and rear iron sights are aligned. I'm sure if the protective Shield on the Liberty was not there, the red-dot would align perfectly. But for my application and MacGyver abilities, it does the job.Just don't tell my wife how much I actually paid for it, and I'll be fine. 10/10 would recommend.

The plate itself is perfect fit great and mounted right up the only issue I had was the threaded pin posts one of them snapped as soon as I torqued it , thankfully there was a spare other than that 10/10.

I’ve searched all over for the right figment plate this for an Sig Sauer P320 M18.

Doesn’t support the holosun I ordered. Expensive mistake

The plate fit my P320 perfectly to allow my optic to mount to it. Very low profile but still sturdy enough to keep the optic in place through over 1000 rounds.

High quality metal and finishing, well machined holes and bevels, fits into mounting plate location on rear of Sig M18 perfectly, T-Lok backing threads system works well. These are the reasons it's getting 2 stars instead of 1.This is because: the listing for the plate clearly (as of the time of this review) states that it is compatible with the "P320 M18" - yet the height of the rear sight is nowhere near correct. Comparing with the removed factory sight (which comes off when you remove the factory top cover) of the M18, the height of the rear notch is at least TWICE as tall as required for alignment with the front sight. Despite seeing the huge difference in sight notch height right away when I received it, I gave it a shot anyway and installed it completely along with the optic. Nope! Using a 9mm Sightmark laser boresight to confirm, the massive height of the rear notch means horrendous misalignment using iron sights. The Holosun 507C sight I put on it couldn't even adjust aim point low enough in the glass to compensate even at 10 ft. When aligning the Holosun aim point with the Sightmark laser from the barrel at approx. 15m, the built-in rear sight of this plate was so tall it obscured the holograph aimpoint too.I have no idea if the other Sig models it claims to be compatible with have such tall rear sights that this might work well on, but for the M18 that it claims compatibility with it is completely not correct for the backup iron-sight ability it's supposed to provide.

Fits perfectly on my X5 legion. Also love that it came with 3 different sets of screw lengths for mounting different dots. Good fit for my holosun 507comp.