I have two Sig P320s one is a 40 and the other with 3 slides. 2 of the slides are 9mm (one is RX) and the other is a 40/357Sig.

My question is how can you tell the difference between a 40 or 9mm slide (if there is a difference). I see no markings on the slide itself to give an indication.

The barrels seem to fit in either well and I can tell no difference.

Suggestions are welcome !

My 40 and 357 barrels will absolutely not fit in my 9mm slide.

quote:

Originally posted by RichN:
My 40 and 357 barrels will absolutely not fit in my 9mm slide.

It seems with the musical chairs I was dealing with slides and frames, I thought they could fit both. You are correct, the 40 will not fit into the 9mm.

Just out of curiosity, do the 9mm barrels seem particularly loose in the .40/357 slides?

As I recall, it's not just the P320. My P229 would be the same, also the SigPro, any SIG I've ever owned would require a slide change as well as the barrel if you want to change calibers.

The only exception is a 9mm conversion barrel. I've had one made for a P229 .357sig. The barrel was custom made then fitted and was fine with the .40/.357 slide. However, if you are using a factory 9mm barrel, you would need a 9mm frame with any SIG.

There is a reason the caliber exchange kits include both barrel and slide.

There is a dimensional difference in the two slide I've been told.

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

quote:

Originally posted by Il Cattivo:
Just out of curiosity, do the 9mm barrels seem particularly loose in the .40/357 slides?

Once I figured out which slide was which, I did not try the 9 in the 40 slide, so I have no idea. Maybe the next time I am taking them down I will check.