On the fence on this one
...
It seemed with the factory sights on my Beretta, the 165gr was the more accurate bullet, all distance's taken into account, however, I did not like those sights, especially the 2 dot rears. To narrow/close together, for clear separations, with these eyes, so I went with some wider rear 2 dots.
However, since I got a combo of new sights for her, rear 2 Dot Night Sights, white/glow-orange, and a front Trijicon night sight, white/glow-green, and now that I have them set, and the rail mounted Laser Max dialed in, I'm gonna go thru 300 rounds (total) of the 180gr vs the same of 165gr, and make my decision of which offers both, all distances shooting, along with rapid ,reacquiring target, shots with the most accuracy/consistency.
I would suggest you do the same when you get your 40cal, get equal amounts of 165gr and 180gr, and start off with 50-100 of the 165gr, then the same with 180gr, then take 50 of each, and load one mag with 165, and the other mag with 180gr, and you should be able to determine what gr weight bullet is best for all around shooting.
Enjoy
LS