I found some 150g Federal HST micro rounds this wekend at Cabela's. Based on testing, rvfiews and forum feedback, they appear to be a top choice. I plan to hit the range this week and try them out. I only have about 250 rounds through my Sheild, but is has yet to have eny hiccups feding ammo. It is currently loaded with Hornaday Critical Defense 115g, shoots well, feeds great and it is wasy to find.