I've talked to Hornady about this exact subject, and they stated the 225 spire point would expand at .375 velocities. They did state, however, that the 220 FP would expand more reliably. I also talked to Speer about their 235gr HotCore bullet, and they stated it would expand if I could get the velocity to around 2100+ fps.
I'm in the process of getting some of the HotCores, and will shoot them into wet newsprint to see how well the expand.
