I have shot 175 grain Frangible +P practice loads at work that barely cycled mine. It was crappy practice ammo from Winchester that didn't run well in much of anything. We weren't even supposed to shoot it in our duty guns. My FNX-45T was brand new then, and it would FTF, or stovepipe if you limp wristed it at all. If you stiff armed it, it would cycle okay with about one jam per mag. After I got it broke in better it was a little better.
That is the only light ammo I've shot in mine, and it was of known poor reliablity in other guns. My FNX-T has ran 100% with everything else I've ever ran in it. It just gobbles up everything else I've put in it.
I know this is anecdotal at best, but if it were me, I'd probably have to run a bunch of any light weight defense load before I trusted it 100%. Of course, for a defense load, any of us should do that anyway I guess. If I wanted to try the Cor-Bon 165's, I'd probably just make sure my pistol was broke in well first (to keep from wasting expensive ammo), and then try it.
I keep mine stoked with the Ranger RA45T's, and it loves those really well.:smile:
Sorry I can't add more, but I hope that helps a little bit.
ETA: looking them up, the Winchester load I tried was a 175 Frangible at 1000fps, vs. the Cor Bon loads listed spec of 165gr. @ 1250fps. If I were a betting man, I'd guess that the Cor Bon would probably cycle a lot easier. That's a pretty warm load, it looks like.:smile: