I am going to buy a second slide for my P320 Full pistol. This is so I can install a red dot without sending my only slide out for machining.

Sig price is $300 including the small parts. Jagerworks has their slide for $200, but without the firing pin, etc.
Any recommendation for a slide manufacturer?

I am going back and forth on the DP Pro vs the RMR Type 2. Any suggestions on the sight are welcome.

I personally like sticking with the Sig slides but if I were to go outside of that, I’d probably go with a Zev Tech, but I think they are only RMR cut:

Zev Tech P320 Full

Another option; buy a slide off ebay, and send it for machining. Primary Machine will mill the slide to fit your specific optic, exactly. Because the cut is an exact fit and not simply a plate, the cut helps retain the optic and reduces stress on the attach points. They're also inexpensive.

I'm the wrong person to give recommendations on optics, but I like the Delta Point Pro because it's got a big window, and also the Trijicon SRO for the same reason.

I like Trijicon products; always have. There's less expensive available, and the RMR's have small windows. The SRO has a larger field.

Pick the optic you want; get the slide cut for your specifications.

Me personally I would get a SIG slide. But that's not based on an personal bad experience on the particular Jagerworks slide but just my experiences on other aftermarket slides on other platforms which have always had various issues. If you are getting a slide for serious use get an RMR. That's just the best option. If you are getting one to play it doesn't matter very much but getting the RMR footprint gives the broadest set of choices. Never get a slide matched to a single specific optic without understanding the downside. When that optic has issues its not a guarantee that another one will fit. Every MFG of sights has tolerances and the good machining guys take that into account and the RMR and DPP don't depend on the machining cut for stability. Since SIG doesn't have an RMR cut you have to deal with that but depending on the cut you can get L&M has a very low cost situation for that or of course if the slide has no cut then mill it for what you want.

Thanks for all the replies. The recommendation of buying a slide on ebay and having it machined to fit the optic may be the best option.

So the Sig OEM slide is machined to fit the DPP, but to install a RMR 2 I would need an adapter plate?

I am not an expert on sig slides and optic mounts since I use RMR's pretty much. But I think a sig slide depending on generation can be romeo1 or romeo1pro (which is DPP). I know that L&M precision can convert both of those to be RMR footprint. I know you can get adapter plates on the M17 to go DPP to RMR because I have done that several times. The guys that made one of my adapter plates are advertising they will soon have a romeo1 to RMR plate for those slides but I don't know if its actually available or any issues. Maybe someone that tracks this can expand on that. I won't use a sig optic at this point so I haven't followed it closely.

"Today" I am thinking that the RMR 2 would be simpler, as I would not need extra tall sights. Also for my CC pistol I would be using a RMR, so I may as well get used to the smaller window.

If I go with the RMR 2, it would be best to buy an un-milled slide and have it machined? Or buy an optic ready slide and use an adapter?

I am not aware of any RMR mount that doesn’t need suppressor height sights for them to be usable. Me I’d get an unmolested slide and mill it,

The Romeo2 is due out soon and would be a good match for slides with a rear sight plate as it has suppressor sight rear sights built into the base.
https://www.recoilweb.com/sigs...ter-mrds-157068.html

I'm glad I held off on getting a 320 Xcompact RXP as this is more what I'm looking for.

Like all things sig (and not to single them out others too) the date of the R2 is not known with certainty. Maybe year end according to some who might know, but sig has a history of not making any dates often by a lot. Its quality is unknown. The date of a revised V1 to fix whatever is wrong is unknown. Production availability is unknown.
In the meantime if you get a proven RMR (or DPP or whatever), a set of suppressor sights and mill a slide for it and then you can shoot to your hearts content with a proven optic that will last for years or until the next great thing arrives. Since the DPP already has the ability of a built in rear and the M17 plate I have has a built in rear I'm wondering what magic that might have versus just using a traditional suppressor sight in the dovetail. I don't see any magic, but sometimes I overlook things.

I would recommend getting a Professional Series genuine SIG slide.
It is the best P320 slide.
1) Has rear dovetail
Fixes cover/slide combo plate
2) Has top-down cover plate screws.
Fixes (bad idea) internal screw
3) Milled for R1P, DPP and d/t for RMR