You are really not trying to reduce the velocity that much, and I can not imagine getting into trouble with most any powder you want to use.
I do a lot of this stuff myself, and like to use faster powders like 3031 or 4064 for this work.
But H4895 is the all time favorite for reduced loads, with recomendations for such from the manufacturer. As per Hogdgon, H4895 may be safely reduced to 60% of max.
Interpolating from the Lee manual shown above: 48 to 49 gr H4895 should put you to 2800 fps with a 150. According to the Sierra, 52.8 gr H4895 will do the same thing. You will never know exactly where you need to be until you run a few loads over the chronograph.
Personally, I would consider going all the way down to 2600 fps for my freind if shots were not going to be over a couple hundred yds.
