Hi folks, I bought a used P320 at a lgs and which I thought was a compact frame. Now I'm embarrassed to admit I'm not sure. It came with a 17 round mag and I believe the compact is 15. Can you guys advise on how to find the frame size that I have? When disassembled I see a 1 inside on the polymer, two clock like symbols pointing to different numbers and a M on the lower back strap which I assume to mean medium. Any help is very appreciated.

17 round mags could come with a full size gun or an X-carry model. The X-carry is compact length, but a full-size grip like a Glock 45.

Overall length on a compact or X-carry length slide will be a bit under 7.5".

Overall length on a full size slide will be at least 8".

Is the grip module rounder in the grip or more square in shape with an extended beavertail? If the latter, it's an X-grip of some sort.

If you got an X-carry of some sort, you can just swap the grip module out for a compact for a few bucks and have the compact you were looking for from the jump.

If a 17 round magazine fits flush with the bottom of the grip module, it's a Carry grip, not a Compact.

If the 17 round magazine is a flush fit with the grip module (not actually the “frame” of the P320), then the grip module is either full size or the “Carry.” The 17 round mag will fit and lock into the Compact module, but there will be a gap at the bottom.

The number of slots in the accessory rail on the dust cover forward of the trigger guard varies among the grip modules. The full size has six five slots; the Carry has three; and the Compact has four (yes, the Compact grip module has more slots than the Carry module for some reason).

The last time I checked, the standard (not X-) Carry was no longer cataloged by SIG, but the grip modules are available, both factory and after market. It uses the full size magazine but its slide is the same size as the Compact’s.

Edited to correct the slot count in the full size grip module. Being able to count to six or even five shouldn't be that hard.

This message has been edited. Last edited by: sigfreund,

quote:

Originally posted by sigfreund:
The number of slots in the accessory rail on the dust cover forward of the trigger guard varies among the grip modules. The full size has six slots; the Carry has three; and the Compact has four (yes, the Compact grip module has more slots than the Carry module for some reason).

The number of rail slots is the easiest way to tell them apart at a glance

This might help.

Thanks for all the very helpful replies. It turns out I bought a "carry" frame. I have ordered a Compact frame from Wilson Combat (on sale) and am a happy guy. Thanks again everyone and merry Christmas.