Just bought a P320 X Compact as a new carry gun.  Ordered one of the dual illuminated Trijicon RMRs for it as well with a 9 MOA green dot (can't use LED or holo sights due to astigmatism).

Can anyone recommend me a good adapter plate for it so I can install the RMR on it?  From what I understand it comes from the factory ready for a Delta Point Pro and some other optic... I think a Romeo?  This is my first 320 platform gun so I am not too familiar with them or who makes the plates for them.

CHPWS appears to be the most popular and common, though it also looks like Forward Controls is making a plate as well. I have no experience with either but can virtually guarantee the FCD plate will be outstanding.

Really obnoxious that Sig forced us into their proprietary mounting footprint. I sucked it up and put a DPP on my 320, but it's not a great design.

Have you taken the current plate off?  From what I understand, they're now being made with RMR taps in the slide.  Something to check.

I have not.  I don't have it in possession yet as I just ordered it.  Wanted to try and get ahead of the curve and have a adapter plate ready for when it comes in.  I can wait though and see if has RMR taps on it once it arrives.

I like the Springer Precision setup which includes a rear sight in front of the optic. SP mounts have the optic sit higher than others but it doesn’t bother me.

For the XCompact, I believe you'll lose the rear sight when you remove the optic cover, so even if it is drilled for an RMR, you'll still likely want an adapter plate with integrated rear sight as opposed to a thinner filler plate.

Bobro is a good option.

As it’s already been said check your slides mounting holes as you might already have the rmr holes if you have a newer version. You wouldn’t get the rear sight however.  I personally went with the bobro plate and think it’s a great option.

This, I have the Bobro and it is well worth the $$.

You don’t want to direct mount he RMR on the M17/M18/X5/X-Carry/X-Compact that is cut for the DPP/R1P as the DPP/R1P is a longer optic than the Trijicon RMR meaning that you don’t have anything dampening the recoil being applied to screws. Eventually the screws will shear off and your optic will go flying. You need recoil bosses or an adapter plate that locks into the optic cut for the DPP/R1P so the screws holding the RMR are not taking 100% of the force applied by the recoil. Bobro or CHPWS are the best option to mount and RMR to the P320 with the rear sight plate as the Bobro has an integrated rear sight in the plate and CHPWS has provisions for a rear sight on the adapter plate.

The BOBRO worked for me

That.

My new XSeries slide came drilled for an RMR, but with the R1P/DPP cut of course, so a direct RMR mount was not advisable for the reasons you stated and also because the underside of the optic would not have been properly sealed.  Even if there is no side overlap, there are two unfilled R1P/DPP holes.

The advantage of a Sig slide being pre-drilled for an RMR, however, is that you can use a thinner filler plate, instead of an adapter plate.  That allowed me to co-witness with the Sig Xray3 suppressor-height sights that came on the slide.  I could not co-witness with them (at least not well) using a CHPWS adapter plate.


CHPWS filler plate:





But without a rear sight dovetail, OP needs an adapter plate with integrated rear sight...and then likely a swap on the front sight.