I have been troubled the last few days seeing the P320 FCU get dissected by the Armorer's here, with some nagging doubts about how much all this may, or may not, be seen in my two P365s.
Obviously getting redirected by experts like @
HCM and others about the lack of NDs with the P365 was comforting. Hearing other armorers like @
KevH and @
lwt16 was also extremely helpful. But I still had these scary weird thoughts in the deep crevices of my lizard brain about all this, because as a hands on learner I didn't "know", in touchy-feely terms. Being fairly risk averse by nature, I was seriously wondering about whether I'd have to rejoin GSSF.
So I just spent a useful hour comparing one of my P365 FCUs with the Sig Guy's P365 and P320 FCU disassembly videos, which was the best source I could fine online. I didn't take any parts off my P365 FCU, that was a bit too scary. But I was really struck by how different in execution the two FCUs are. Obviously these are uneducated comments by a random .civ geezer, and I only had the 320 video to compare, but I was shocked, really, by how "agricultural" the P320 FCU was designed/assembled/put together by comparison. The P365 parts and housing looked tightly built, to reasonably accurate tolerances (I assume lots of MIM parts); the P320 looked like it was done by a high school shop class in metal stamping. The 320 TRS is hanging out in the open, almost as an afterthought, the P365 spring is tucked in and under the FCU. The ejector on the P365 is this solid piece of MIM molded into the body of the FCU, the ejector on the 320 is a little steel protrusion stamped when the sheet metal is formed. The P320 sear housing is a little assembly that inserts into the back of the FCU, the sear in the P365 runs within a purpose-milled area at the back of the FCU. I also looked in detail at the firing pin safety block operation in the P365. I also checked my holsters, and the tight fit (JM CK, Vedder, RCS) offers adequate protection against a foreign object ND far as I can tell. I'd never looked quite so closely at my FCU before and this was really eye opening, for me. Decided to keep the P365s and get on with life.