So I have to admit, all the variations of the 320 is a little confusing to figure out and Sig's site isn't much help.

So if I bought a 320x with the RDS plate like this...


The rear sight is connected to the RDS plate correct? Assuming so, if I remove the plate and install an RDS, is there a dovetail to mount a rear sight or do I have to buy an "RX" or "Pro" model to get the rear dovetail?

Also, is there some kind of guide that lists what slides are milled for which optic? I ask because apparently the M17 slides are milled for Leopold DPPs but I'm assuming others are milled for the romeo sight which I think has a different screw pattern?

The DPP will drop on and Leupold has a little BUIS that can drop in the rear of the optic. I personally don’t like the DPP, I tried to but that button sucks.

You can get a mount with an integrated rear sight from Bobro here as well as a taller Dawson front, and then an RMR will mount which I much prefer.

The never slides are supposed to have holes in them for an RMR but there’s no recoil lugs for it and eventually the screws are going to shear.

that XFull will mount a Delta Point Pro, to which you can add the rear adjustable sight for about $70 or a simple notch sight for like $9

it will also fit the SIG Romeo1Pro which I prefer over the Delta point, and it has a rear sight notch built in.

SIG also taps these slides for RMRs now, you'll need an adapter plate which replaces the filler plate. CHPWS makes one, they also make one with a dovetail for a rear sight, BoBro Makes one with an integrated rear sight, it's a bit thicker but by all reports very high quality.

Here is a similar style P320 slide that uses the same cover plate and rear sight as you show in the picture.

I removed the plate and site and installed a Bobro plate that has a rear sight attached.  

The Bobro plate allowed me to fit the Tijicon RMR.

The Sig Front Suppressor sight was also added.

Thanks for the info so far. Just to make sure I'm clear on this, the "Pro" and "RX" slides have the same optic cut but have the rear dovetail machined in as well correct? Is there any other difference between the "X" slides and the "PRO" or "RX" slides?

I know some of them are milled for an LCI and some aren't. Anyway to know which is which ones are LCI without seeing it by model # or name?

I don't think so, Sig is kinda ADD when it comes to changing up manufacturing and models.

Have you tested POA/POI with that iron sight set up? In my experience you need at the very least a .375” height front sight. This is also recommended by Bobro. That said all of my 320s with the Bobro plate have required a .390” front sight and one even needed a .400 to get the POA/POI dialed in at 25. Just FYI.

I have not.  Still having issues with my shoulder after rotator cuff surgery.  Will Report as soon as I have the information.  Thanks for information on your experience, it is noted.

Someone makes a plate now that has the bosses built in. It is basically a thin sealer plate like Trijicon recommends but has front bosses. I think it was CHPWS.

The Bobro has bosses. The plate itself is locked into place via the grove where the sight plate normally goes.

Attached File

I found a newer full length slide (probably from a Pro or RX model?) that is factory drilled for an RMR and has Sigs Xray suppressor height sights. I'm going to get a CHPWS spacer plate with the RMR lugs and a sealer plate which will still allow me to co-witness the factory sights.