Let’s assume I have a 365 9mm with manual safety and a 365 380 with no manual safety; According to what I have read the grips and FCU on these two models are identical. My question is if I place the the slide from the 380 with no manual safety onto the grip module of the 9 mm with manual safety will the safety work as it’s suppose to, and will the 380 magazines work in the 9 mm grip module??

Yes they will as long as the upper is all .380 parts.

I just got a .380 and put a manual safety in it, along with a grip module with the safety cut. Works fine. The newer FCU's are a little different. You can go on safe with striker uncocked which locks the slide. On safe with striker cocked doesn't lock the slide.

Older receivers cannot go on safe with an uncocked strikers. I noticed the older receivers have a silver sear, whereas the newer ones have a black sear. The safety lever itself is the same.

More odd Sig running design changes that are un-announced and don't make a whole lot of sense.

Thanks for the reply. I have noticed that the two gun shops that actually have the 380 in stock have them with no manual safety.

I’m guessing that if I can quell my desire to get the 380 version of 365 for a few months they will come out with an exchange kit for the 9 mm version in 380 ACP then I can swap them out with my current 9 mm And make a determination of which I would rather carry

^^^ I considered that, but a top end swap from Sig is probably going to be $400, and the .380 can be had for about $500, so it's not that cost effective. But if the top end is about $300 then maybe that would be OK.

I wanted it to see how an optic fits with the iron sights, since you don't lose the rear sight like on an X or XL. But on the .380, optics sit too high and don't cowitness with the irons. Not sure what height sights would work, suppressor height might be too high.

Lately I’ve been thinking along the same lines as you. For $100 more it probably pays to get the complete gun in 380. I’d probably be willing to go to $520 so this week I’ll hit the streets again.

My arthritis has been plaguing me lately and I’ve been carrying either my 238 or Glock 42 both of which are fantastic; so I’m committed to staying within that weight class and power level for the rest of my shooting days. Thank goodness I reload 380 and have a good supply on hand.

Ok lefty this morning I did it! I went to my local gun shop and brought a couple safe queens with me for trade; came home with a new 365 380.

I felt a sense of relief to unload the two guns and get the new 380. I’m sure it will get plenty of shooting time as well as carry time. Since I already have the 9mm model this gun fits perfectly in my Milt Sparks holster. Thanks for the help

Congratulations on getting the new Sig 380.
Have you had a chance to shoot it yet?
I’m waiting for mine to come in at Sportsman Warehouse in a few days. It might replace my LCP Max or simply share in EDC duties. I already ordered the XL grip module and a 12 rd mag.
This will be my first Sig.