FWIW, My 9MM HK USP Expert owners manual sanctioned the use of +P+ ammo, with an admonition about increased wear. The Glock information packet that is, or at least used to be, provided to police departments indicated that use of 9MM +P+, IMI black tip carbine, or "any commercially manufactured ammunition" could be used in Glock pistols. The Glock info packet went on with something to the effect that service life would not be reduced. I realize this information differs from information supplied in the regular commercial owners manuals.

The OP's questions generated some interesting discussion. I think worry about use of 9MM +P or +P+ is the most discussed handgun ammunition issue I see on enthusiast forums.

Thanks for all the comments and information.
I really do appreciate the wisdom available here on SigForum.

Correct me if I am wrong but +P is a saami approved specification where +P+ is basically however much powder you can cram in there, hold on to your butts. So it’s best to stick with a known entity 9BPLE etc.

I’ve shot quite a bit of 9BPLE in my Sigs over the years. I have quite a bit of it as SHTF ammo. To be honest, it doesn’t even feel that hot to me. I don’t see any wear issues or other problems. The +P+ 9mm doesn’t seem like its hurting the Sigs at all. That being said, I’m not an armorer, so your mileage may vary.

I've used a fair amount of 9MM +P+ Federal 9BPLE 115, Winchester Ranger 115 +P+, and a small amount of the Remington 115 +P+. I would not loose any sleep over using any of these manufacturers' +P or +P+ in a quality 9MM pistol.....ymmv