There is quite a hit of published load data on the Hodgdons site for plated bullets. There are Berrys plated bullets that are described as being HEAVY PLATE that are rated for higher velocities than 1,200 fps. As long as you stay under Xtreme's recommendation of 1,200 you should be just fine with Hodgdons data for similar bullets.

I have loaded thousands of the Xtreme 9mm bullets. Occasionally they have had FMJ versions and those worked EXTREMELY well (pun intended!)...

Cheers!