I use the combat or # 3 sight picture (using the images others have pasted in posts) on all the 9's i have. That includes compact MP, full size MP and a PC Shield. And I've have always and only used 115 gn ammo.

That sight picture works well for me and my skill/eyesight. In fact i use it on my .22's as well. Cant say that's what others use or are supposed to use, just pointing out I use it with decent to good results with that ammo.

edit- I should add that the high % of my range time (and I've ran thru a decent amount of ammo) has been indoors and 10 yd max. It is quite possible the different ammo grains could have an effect on accuracy as one stretches the distance.