I have a FDE 320 Carry in 9mm and love it! If I transfer the slide to an X Frame, will there be any performance issues since the 320 slide does not have the lightning cut?

You'll be good to go. Sig released the X-Series grip for cases just like yours. Its an upgrade to your stock P320 that will make it feel and look better.

Thanks Squad13...now if Sig would only make it in FDE vs Black!

The P320 Carry slide works just fine on the X-Carry grip.

The only thing to keep in mind is that most of the older 17 round and 21 round magazines won't work with the X-series grips. So you may need to buy new mags, or modify your existing mags.

The most recent iteration of the 17 round magazine will fit the X-Carry grip module. These are denoted by a different baseplate, with a square retainer and a circular SIG logo. The older 17 round magazines, with a round retainer and a Sig Sauer logo, will not fit in the X-Carry grip.

The new and old version of the magazine have the same part number, so if you're ordering online, you'll want to specify with the retailer whether they're the new version or the old version.

Here's a comparison photo. New baseplate on top. Old baseplate on bottom.



If you have some existing 17 round magazine with the older baseplates, you can modify the baseplates by cutting/grinding off the "ears" that stick up. That will allow them to work with the X-Series grip modules.



Otherwise, you'll have to replace the old baseplates with compatible baseplates. Sig has a baseplate replacement kit, part number KIT-MOD-MAG-FLR-PLT-BLK / UPC 798681591862, but they're in very short supply. There are some aftermarket replacement baseplates that are compatible with the X-series grip modules, like the Springer Precision 0.25" basepads. Here's a shot of my P320 with X-Carry grip module, using one of my older magazines with Springer Precision basepad installed.




Similarly, the 21 round magazine baseplates have been modified as well.

The old version has a larger round SIG logo with sunken lettering, a round retainer, and a taller textured portion on the sides of the extension. It is not compatible with the X-Series grip modules.




Only the newest version, with half-height texturing on the side of the extension, square retainer, and smaller round SIG logo with raised letters, will work with the X-Series grip modules.



17 round magazine > Old 21 round magazine > New 21 round magazine: