I'm pretty much exclusive with BBI (black bullets international). Just got in an order of 1000, so that will put me at 4000 so far.
I ordered a sample pack of blue bullets, but my M&P 5" Pro just doesn't like them for some reason. The diameter and OAL is the same as BBI, but they have a little bit different ogive and hang up going into the chamber. I'll experiment with seating them at different depths and see if that clears up the issue.
What bullet did you get? I've never had any of my M&Ps not feed. Are you loading long like the big boys and their STIs?