But it would seem to me that they should expand. After all they are a pistol bullet and the velocities are relatively the same.
That's kinda the was I saw it too, and really wondered if that guy knew what he was talking about. But he clearly wrote "you'd better hit bone because it will not expand if you don't". That't the trouble with e-mail about stuff like that vs. verbal conversation. With e-mails you can't get a feel for the individual you're dealing with.